the proposition that somehow ukraine doesn't exist as an independent country. what ukrainians are showing every single day is, of course, exactly the opposite. >> diaz: the secretary of staten is on a six-nation european blitz aimed at keeping allies in lockstep. cbs' christina ruffini is i cbs' christina ruffini is in poland near the border with ukraine. >> reporter: the u.s. secretary of state went to ukraine today, at least technically. in a show of solidarity, he met with ukrainian foreign minister kuleba at the ukrainian border and walked across the boundary as a show of reporting. secretary blinken went to a significant center where 3,000 refugees are staying. he said the whole world is inspired by what ukrainians are doing and united against russia. russian attacks on ukraine have sent shock waves through europe and nowhere have people felt it more than here in poland where more than 700,000 refugees have