cssage to pyongyang. >> north korea to me, is a cancer on the earth. >> reporter: cindy warmbier lashed out at north korean dictator kim jong-un, calling u.s. diplomacy with him a karade. ip how can you have diplomacy with someone that never tells the truth? he lies. he lies. he lies. >> reporter: she expressed doubts about president trump's uteadfastness. >> unless we keep the pressure on north korea, they are not going to change. and i am very afraid that we're going to let up on this pressure. >> reporter: warmbier's son, otto, was detained for a year and a half in north korea for ainegedly pulling down a propaganda poster. >> i beg for any kind of public protection. >> reporter: he was returned to the u.s. in june 2017 in a coma and died six days later. atesident trump admits warmbier was brutally tortured by north korea but has defended kim. >> he tells me that he didn't know about it, and i will take him at his word. >> reporter: warmbier appeared