Transcript for Trump arrives for summit, greeted by hundreds of people waving American flags

Agreeing to meet for a second time now with Kim Jong-un. The president waving from his car today, and Kim Jong-un, after traveling in his armored train through China, then getting into a motorcade to finish the trip through Vietnam. You can see his bodyguards there jogging alongside. And with hours to go before they meet now, the president tonight, and what he's now signaling about this summit. ABC's Jon Karl, right here in Hanoi with us tonight. Reporter: A half a world away from the political turmoil back home, president trump received a lavish greeting in Vietnam. Hundreds waving American flags. "Tremendous crowds," he tweeted, "So much love." After a nearly 3,000-mile, 65-hour journey, Kim Jong-un stepped off his armored train in Vietnam to a red carpet welcome. The grinning north Korean dictator outpacing one of his aides who scrambled to keep up. The journey offered rare, unscripted glimpses of the reclusive leader. Japanese TV capturing him punching a cigarette while his sister held a crystal ashtray. In Vietnam, a more familiar scene. Kim's elite security detail in their dark suits jogged alongside his armored Mercedes for summit two, both leaders are hoping to achieve something summit one did not. Concrete results. Kim is seeking relief from crushing economic sanctions. President trump is saying north Korea can become an economic powerhouse if Kim agrees to give up his nukes. But U.S. Intelligence officials say they see no sign north Korea's ready to do that. The regime is committed to developing a long-range nuclear-armed missile that would pose a direct threat to the United States. Reporter: Last year, president trump called on the dictator to give up his nuclear weapons and fast. Mr. President, did he agree to denuclearize? Sir? We're starting that process very quickly. Very, very quickly. Absolutely. Reporter: But this year? I'm not in a rush, I don't want to rush anybody. Jon Karl with us live tonight here in Hanoi. Jon, you and I will be watching as the summit unfolds here in Vietnam. And the president knows full well that as he prepares for this summit now, his former fixer, Michael coalen, will be testifying against him on capitol hill. And there are reports tonight that the president will be watching some of that hearing? Reporter: David, Cohen will Bech thing late into the night, into the early morning hours here in Vietnam, but I would be shocked if the president doesn't find a way to watch at least some of that testimony. In terms of the response, the white house, for the most part, is leaving it up to the president's outside supporters, but the president considers himself the ultimate counterpuncher, and you can be sure that the response that really matters will ultimately come from the president himself.

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