Transcript for Leaders from North, South Korea vow to sign peace treaty to end war

Next to the remarkable images, Jim Jong-un stepping over the border into south Korea. Then both leaders stepping back into North Korea. It was really something to witness, as the world was watching. Both declaring the war is over. And what president trump said today with his face to face meeting coming next. Terry Moran, in South Korea. Reporter: High drama in the dmz. Kim Jong-un, emerging from north Korea. His phalanx of bodyguards slips away and he strides alone to the border. A warm handshake with south Korean president moon jae-in. And then, with that step, Kim makes history. The first north Korean leader to set foot on south Korean territory. Unscripted, the two leaders then cross back into the north as if to show that fearsome border is just a line on the ground. This summit marked by pageantry. The men, also introducing their wives. Kim Jong-un's wife all smiles. In the end, the two leaders promising to sign a peace treaty this year, formally ending the Korean war and pledging the denuclearization of the peninsula. Sealing the deal with a bear hug. "We are one nation," Kim declared. But beyond this summit, the family of American Otto Warmbier reminding the world of the brutal nature of Kim's regime. Filing a lawsuit this week accusing North Korea of the torture and murder of their son in a north Korean prison. And in Washington, president trump, whose tough talk about fire and fury changed the dynamic here, optimistically looking forward to his own meeting with Kim. I'll be watching people that failed so badly over the last 25 years explaining to me how to make a deal with North Korea. I get a big, big kick out of that. But we are doing very well. I think that something very dramatic could happen. Terry, from just south of the dmz tonight. The president says they've narrowed down the possible locations for the summit? Reporter: Yes, it's been tough. It needs to be close because Kim Jong-un's airplane only has a range of a couple of thousand miles. It could be Singapore or Mongolia. We'll have to see. Thank you. And the president also

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