Transcript for What happened at the U.S.-North Korea summit in Vietnam

It was an abrupt ending to this sacking US North Korea's summit a working lunch in a signing ceremony canceled. President trump at a press conference explaining what happened. Basically they won at the sanctions lifted. In their entirety and we couldn't do that. The resident said Kim Jung and was willing to dismantle North Korea's young young nuclear complex but in return the North Korean leader won it all sanctions lifted. Mr. Tom said that was not enough you'll have to be prepared to walk. We actually had papers ready to be sign but. It just wasn't appropriate. I want to do it right still the president insisted the summit didn't end badly I think the relationship was very warm and where we walked away it was. Very friendly walk the president was asked if he confronted him about the death of American college student on a warm beer. He spent more than two years in North Korean prison in died shortly after he was released in 2017. You covered in a renewed of the case very well. But he knew it later. Earlier in the day a remarkable scene the reclusive North Korean leader engaging with American reporters. Can gun and was asked if he is ready to. I'm not willing to do that and when you're right now. After the summit in Singapore last summer the White House said Kim Dong ying was willing to give up his nuclear weapons before sanctions were lifted. In their hands on that agreement differently or he now changed his terms president Tran says toxic in the US and North Korea will continue. Here average ABC news you know why.

This transcript has been automatically generated and may not be 100% accurate.