if mexico had hoped donald trump's promises on the campaign trail had just been bluster and bravado, it looks like the country's in for a disappointment. first he ordered the building of a border wall. now the white house is threatening a new tax on imports. mexico's president, enrique pena nieto, has cancelled a meeting with his american counterpart — a meeting mr trump said would be fruitless. if the two countries are heading for a possible trade war how much money is involved? official figures for 2015 show that the united states exported nearly $270 billion of goods and services to mexico. in return — mexico exported more than $316 billion of goods and services in the same year. that meant the us had a trade deficit of nearly $50 billion the white house says that figure was $60 billion for 2016. nick bryant has more. donald trump's new executive toy. his first ride today on air force one, that potent symbol of us presidential power. but it was the cancelled travel plans of the mexican president that were at the centre of a diplomatic storm. his plane will stay grounded after a summit between the two leaders scheduled for washington next week was abruptly called off. this mexican stand—off is over the great totem of the trump presidency, the wall he's determined, notjust to build along the border, but also to get mexico to pay for. but in an angry speech last night, the country's president, enrique pena nieto, said he wouldn't foot the bill. so, shortly before leaving the oval office this morning, donald trump decided to conduct his diplomacy by tweet. by the time he spoke in philadelphia, the mexicans had announced the summit was off, and that earned a public scolding from president trump. the president of mexico and myself have agreed to cancel our planned meeting scheduled for next week. unless mexico is going to treat the united states fairly, with respect, such a meeting would be fruitless, and i want to go a different route. almost a week into his term in office, it's already becoming clear that donald trump is changing the presidency more than the presidency is changing him. 0n prime—time tv last night, the former property tycoon gave a tour of the country's most prized piece of real estate and it was vintage donald trump. i don't want to change too much. i can be the most presidential person ever, other than possibly the great abe lincoln, all right? but i can be the most presidential person. he's still obsessed with the crowd size at his inauguration. a sea of love. but in a new interview with fox news, he turned his attention to the group calling itself "islamic state," saying its fighters were sick and demented. the people that we're going against, they don't wear uniforms, they're sneaky, dirty rats. and they blow people up in a shopping centre. and they blow people up in a church. these are bad people. the presidency is travelling at a hurtling pace. the late—breaking news that he's now calling for a 20% tax on mexican imports to pay for the wall. donald trump is clearly revelling in his seat of power, whether it's in the oval office or at 30,000 feet. beautiful. great plane. nick bryant, bbc news, washington. britain's prime minister theresa may has arrived in america at the start of a trip which she hopes will pave the way for a post—brexit trade deal with the united states. she'll be the first foreign leader to hold talks with donald trump at the white house on friday. 0ur political editor laura kuenssberg is travelling with mrs may. 0pposites attract. theresa may's hope. but how close does she want to get to him? the prime minister made a quieter arrival, making her way down the windy steps in philadelphia. her convoy speeding towards her debut in trump land, here to make friends. no hate, no fear. a reminder right outside the 5—star hotel where they were both to speak, donald trump has many enemies as well. the prime minister's warm up act was the president himself. is he ready for her? i'm meeting with the prime minister tomorrow, as you know. great britain. i'm meeting with her tomorrow. i don't have my secretary, they want to talk trade, so i'll have to handle it myself. laughter which is ok. then it was her turn, with, as you would expect, fulsome reference to the friendship across the atlantic. it has been america's destiny to bear the leadership of the free world and to carry that heavy responsibility on its shoulders, but my country, the united kingdom of great britain and northern ireland, has been proud to share that burden and to walk alongside you at every stage. applause cheering but this is much more than a meet and greet. theresa may came with a serious message for republicans and the world. under her leadership, no more western conflicts like iraq, or afghanistan, she suggested. this cannot mean a return to the failed policies of the past. the days of britain and america intervening in sovereign countries in an attempt to remake the world in our own image are over, but nor can we afford to stand idly by, when the threat is real and when it is in our own interests to intervene. we must be strong, smart and hard—headed, and we must demonstrate the resolve necessary to stand up for our interests. and a warning perhaps directed at the president over an assertive russia. when it comes to russia, as so often it is wise to turn to the example of president reagan, who, during his negotiations with his opposite number mikhail gorbachev, used to abide by the adage — trust, but verify. with... applause with president putin, my advice is to engage, but beware. noticeable as well, her praise for the republicans and president trump's controversial win. because of what you have done together, because of that great victory you have won, america can be stronger, greater and more confident in the years ahead. even before she touched down though, theresa may had a taste of how much political trouble closeness to president trump could cause. number ten believes the risk is worth it, because there's a big opportunity as well, but this new friendship could cause fireworks every time donald trump's speaks his mind. like suggesting torture, banned under british and international law, works. i want to do everything within the bounds of what you're allowed to do legally, but do i feel it works? absolutely i feel it works. the prime minister was adamant britain won't change its laws and signalled we might stop sharing intelligence with america if torture was brought back. here among the republican top brass, the idea is unlikely to fly. the deep—seated policy in american culture is not to torture. so theresa may is right and president trump is wrong? i didn't say that. just one of many awkward subjects the pm and president could discuss tomorrow, a test, even in politics true friends tell the truth to one another, not merely platitudes, or what they want to hear. nile gardiner is director of the margaret thatcher center for freedom at the heritage foundation conservative think tank in washington. and he was a foreign policy advisor to the former prime minister. and adviser to mrs thatcher, several media outlets are saying that the relationship between theresa may and donald trump will be a new special relationship in the style of margaret thatcher and ronald reagan. i think it remains to be seen whether or not there will be a parallel stop i must say this, i think theresa may is off to a flying start. it was a very good speech today in philadelphia. quite warmly received by the congressional republican leadership. she received a number of standing ovations. it was a very forceful message that she delivered, a very strong message of support for the anglo—american special relationship. talk of a self—confident sovereign britain on the world stage following the brexit referendum and great britain that will stand shoulder to shoulder with the united states in the face of an array of threats. i thought she did extremely well and i think it is a very good start, actually, to the relationship between theresa may and the neutron presidency and the very important republican leadership on capitol hill. their support will be vitally important, of course, for putting together free trade agreements. and britain, after rejecting europe, will need some kind of new special relationship. you can speak to diplomats doubt actually whether the special relationship ever really existed. actually whether the special relationship ever really existedlj think relationship ever really existed.” think the special relationship has existed for the last 70 years. i think it has been weaker in the last few years under president 0bama who had a lukewarm approach to great britain. he was also very mocking about brexit and he basically declared that britain would be at the back of the queue for a free trade deal. the new reality, of course, is that great britain is now at the front of the queue for a free—trade agreement with the united states. the special relationship, i believe, is critically important to both the united states and great britain. it does exist. long may it continue and i think on both sides of the atlantic we have leaders who are committed to advancing the special relationship and that is very, very good i believe that the trans— very, very good i believe that the tra ns— atlantic alliance very, very good i believe that the trans— atlantic alliance and the cause of freedom on the world stage. they are not entirely on the same page, are they? he has infamously said that torture works as an interrogation technique. she has already said that she condemns torture and her view wand that will not change. —— her view on that will not change. —— her view on that will not change. —— her view on that will not change. i do not think that will bea not change. i do not think that will be a big part of discussions in the white house. but it would mean that britain can not use us intelligence if it suspects it comes from torture. it should be pointed out that there is no clear policy from the new administration in regard to enhanced interrogation techniques. and so there is no policy set in stone on that and i do not expect it will be an issue that will dominate the discussions which overwhelmingly focused on the us, uk free—trade agreement. foreign policy issues as well including the russian threat, it rhymes, syria, iraq for example. —— in rana, syria. it rhymes, syria, iraq for example. -- in rana, syria. thank you very much. the new president of the gambia, adama barrow, has flown back into the country. mr barrow was inaugurated last week in senegal for his own safety while regional leaders persuaded his predecessor, yahya jammeh, to step down. he is now in exile in equatorial guinea. here's alistair leithead. a long—awaited return for the gambia's new president. it is the first time how he has peacefully passed from one leader to another. adama barrow was inaugurated in senegal win the man he defeated at the ballot box refused to leave. expectations are high. the former dictator, yahya jammeh, went into exile last weekend after weeks of treasure from neighbouring president. a rare case of african leaders strongly policing democracy. the threat of military action from a regionalforce the threat of military action from a regional force helped. the threat of military action from a regionalforce helped. they now provide security for the new president, still unsure with his army's loyalty lies. now he will need fancy footwork to deliver on all the political promises. it is a poor country. young talent often leaves. this is the gambia's top women team. their goalkeeper drowned last year trying to cross the mediterranean. she was 20 years old. her brother thinks she may have hoped to play in europe and so joined a well trodden path. what we believe is that we want to be out and do something for our family or something like that. who knows...m villages all across the gambia, many, villages all across the gambia, any villages all across the gambia, many, many people are taking what they call here the back way to europe. starting here they cross dress and a goal, through mali, through burkina faso to need you where they head north through the sa ha ra where they head north through the sahara desert to libya and from there they tried to cross the mediterranean into europe. fancy new houses built in poor villagers show what reaching europe means. money sent home makes a huge difference here. it is a big incentive. this man is 26. he tried and failed. the family supported its plan to migrate and were disappointed when he came home after a terrible experience. and were disappointed when he came home after a terrible experiencem was so home after a terrible experiencem was so hard. kidnapped by criminals who was imprisoned for one month and then stranded with no money in southern libya he asked the un help him geta southern libya he asked the un help him get a home. there is hope here that a new president can revive the economy and remove the need for young people to leave. it will not happen overnight. rooster rooster in other news: the philippines has reversed its stance on american bases, announcing the united states will now upgrade and advance its facilities on bases in the country. last year president duterte said he wanted us troops to leave and called for an end to alljoint military exercises. authorities in austria have detained eleven men and three women they suspect of belonging to the extremist group that calls itself islamic state. around 800 officers carried out raids in vienna and the southern city of graz. stay with us on bbc news, still to come: we're 30 seconds closer to armageddon. after president trump's inauguration, peace activists move the doomsday clock nearer to midnight. the shuttle challenger exploded soon after liftoff. there were seven astronauts on board, one of them a woman school teacher. all of them are believed to have been killed. by the evening, tahrir square, the heart of official cairo, was in the hands of the demonstrators. they were using the word "revolution". the earthquake singled out buildings, and brought them down in seconds. tonight, the search for any survivors has an increasing desperation about it as the hours pass. the new government is firmly in control of the entire republic of uganda. moscow got its first taste of western fast food as mcdonald's opened their biggest restaurant in pushkin square. but the hundreds of muscovites who queued up today won't find it cheap, with a big mac costing half the day's wages for the average russian. this is bbc news. the latest headlines: the white house has said president trump may tax imports from mexico to pay for his border wall. the mexican government warns that will hurt american consumers. the british prime minister has told an audience of senior american republican party politicians that she's looking forward to talks about a new free trade agreement between britain and the united states. more now on day 6 of america's new president. for the last seventy years, the us—based bulletin of atomic scientists has set the metaphorical time on what it calls the doomsday clock. it's their way of measuring, in the age of atomic weapons, how close the world is to total destruction. on thursday, the group announced it was moving the hands 30 seconds closer to midnight — the symbolic moment when it says the earth would face apocalypse. the recent? donald trump. perhaps most troubling has been too concerned that adding to an already challenging global landscape. the first has been the cavalier and reckless language used across the globe, especially in the united states during the presidential election and after around nuclear weapons and nuclear threats and the second is a growing disregard of scientific expertise which is needed when it comes to responding to pressing global challenges including climate change. a study of four hundred children in the united states suggests girls start to see themselves as less innately talented than boys when they are only six years old. researchers at three universities read a story about a really intelligent person to five, six and seven year old children, without revealing the gender of the main character. at age five, boys assumed the tale was about a man and the girls assumed it was about a woman. at the age of six, the boys still picked men, but the girls were also now more likely to think of the smart character as male. the scientists describe the results as disheartening it's holocaust memorial day — marking the anniversary of the liberation of auschwitz at the end of the second world war. commemorations are being held there to remember the six million jews and others that were murdered by the nazis. our special correspondent allan little has been to auschwitz and met one woman who survived her time there against the odds. 72 years ago this week, soviet troops entered auschwitz. this was not the only extermination camp in nazi—occupied europe. but it was where the evidence was best preserved of the crime that came to be known as the holocaust. on this railway platform, nazi officers separated those chosen to live and work from those sent immediately to die. these pictures showed jews transported here from hungary in 1944. susan pollock, i3, was chosen to live. her mother was sent to the gas. there were no hugs or kisses or embrace. the dehumanisation started immediately. i did not cry. it was just as if i had lost all my feelings. that was auschwitz. this was not a german crime alone. these railway lines extended to almost every corner of europe, and to the active collaboration of norwegian civil servants, french police, polish train drivers, ukrainian paramilitaries. when it was over, a great public silence descended on europe. after the war, the nations of europe were so preoccupied by their own victimhood that they did not pay much attention to the uniqueness of what had happened here. the jews who survived found that the world beyond these perimeterfences did not want to hear their stories. it was only really in the 1960s, nearly 20 years after the liberation of auschwitz, that popular consciousness began to confront what europe collectively had done to itsjews. international law changed immediately. at the post—war nuremberg trials, two new crimes entered the judicial lexicon for the first time, crimes against humanity and genocide. before 1945, if a state wished to kill half its population, there was no rule of international law that said you could not do that. the change that occurred, as we know sadly, has not prevented horrors from taking place, but it does mean that when horrors occur, there is now at least an objective standard which says to governments that as a matter of international law you cannot do what you are doing. it took half a century for those powers to be used. but dozens have been convicted and jailed by international courts for genocide and crimes against humanity in bosnia, rwanda and elsewhere. even so, holocaust denial persists. the internet is full of claims that the destruction of the jews never happened. but the testimony of survivors is a warning to posterity, to us here today. we are not talking about barbarians, primitive society. the germans were advanced, educated, progressive, amongst the european nations. maybe the civilisation is just a veneer. i think we all need to be very careful about any hate propaganda, because it has got the potential to erupt, and then it is too late to stop it. too much less weighty matters. diamonds, so they say, are forever — and the bigger they are, the greater and more enduring the value. take the foxfire diamond, this story of the foxfire diamond began 2 billion years ago when it was forged by size and forces deep beneath the earth. now the largest uncut diamond in north america has been studied by scientists. a lot of people would agree with you. in fa ct, people would agree with you. in fact, a lot of people if they saw that laying on the side of the road would not think about picking it up. diamonds are as mysterious at michu writes, travelling through time and space to offer clues about the universe. this diamonds perilous journey is even more remarkable, splintered by volcanic action that propels them to the surface of the earth. we know by looking at the flat surfaces that there was more. the explosion at the surface, the mining operation, something cause these diamond to be broken and these broken cleavage surfaces someplace that there are other pieces to this diamond. we better go hunting. we do not know if it is the biggest or smaller piece. but somewhere there are other pieces. a reminder, briefly on the top story, the white house has said president trump may impose a 20% tax on imports from mexico to help build the wall to keep out illegal immigrants and drugs. president pena nieto has cancelled his trip to washington and said then takes would hope american consumers. thank you for watching. hello. well, while some of us were shivering on thursday, for others, for example across the north of scotland, it was remarkably mild. a day of contrasts. we are kind of getting back to normal through this weekend. most of us will turn less cold. a bit of breeze, some sunshine but there will be some rain around, too. we are losing the continental feed which brought most of us a very cold day on thursday. we are doing to start to drag air in off the atlantic, and hence that rise in temperatures for the majority. we start the day with a hard frost, one or two freezing fog patches. the odd shower as well, which could cause some icy stretches. it should be a dry start across wales, that fog up over high ground, but that will be lifting, and the temperatures will be on the rise, above freezing for northern ireland. rain knocking on the door of the west of the province. a frosty start for most of scotland. and here i think it is set to be a largely dry day, with some sunshine. heading our way down, across the borders into northern england, cold with a hard frost, some freezing fog patches for sure in the morning, so watch out for those. i mentioned the odd showerjust spilling into eastern counties for a time in the morning, so the risk of one or two icy stretches. but temperatures slowly rising above freezing. down across southern england and into the south—west, we should be above zero. a dry start but some showery rain lies in wait out west. this band of showery rain will start to push its way slowly eastwards, across northern ireland and into the far south—west of england, perhaps the far south—west of wales. another little area of showers pushes up across southern england through the afternoon as well. further north and east, it stays dry but that chilly air holding on for one more day. just two degrees there in newcastle. milder, though, across many southern and western areas. as we head through the evening and night, it gets a bit messy. there will be areas of rain pushing their way northwards and eatwards. some of that quite heavy, actually, so quite wet weather. and a period of snow up over the higher ground of scotland, in particular. but something a little bit clearer will folllow on behind. temperatures could dip late, close to freezing. but for most of us, actually, it will be a frost—free start to the weekend. saturday starts with cloud and some patchy rain, continuing to move northwards and eastwards. behind that, it turns brighter but also with some showers. and one or two of those showers could be wintry up on the high ground. but it will not be anything like as cold as it has been for most of us. double figures in a few southern areas. that milder theme continues into sunday. we could see an area of rain pushing to southern areas. how far north that gets is open to question. best of the brightness on sunday will be further north. across the uk, milder than recently. the latest headlines from bbc news. i'm mike embley. the white house has said president trump may impose a tax of up to 20% on imports from mexico to help pay for his planned border wall to keep out illegal immigrants and drugs. the mexican economy minister has said the idea won't work because it willjust put up costs for american consumers. the british prime minister, theresa may, has said britain and the us should not return to what she called the failed interventionist policies of the past. mrs may was speaking to republicans in philadelphia at the start of a visit that will see her become the first foreign leader to meet president trump. the gambia's new president, adama barrow, has returned home to scenes ofjubilation. thousands lined the streets as his convoy travelled to the capital. mr barrow was inaugurated last week in senegal for his own safety while regional leaders persuaded his predecessor, yahya jammeh, to step down. now on bbc news, it's time for thursday in parliament.