He described the meeting set for Tuesday in Singapore as a "one-time shot" for Kim and characterized it as a "mission of peace", speaking shortly before he left a Group of Seven summit in Canada to fly to Asia.
Agreeing to a troop withdrawal from South Korea would be the worst possible outcome for the summit, said Christopher Hill, a former USA ambassador who ran negotiations with North Korea in the George W. Bush administration.
What can we expect from the summit?
North Korean leader Kim Jong-un is due to travel to Singapore for the meeting.
Jenny Town, research analyst at the Stimson Center and managing editor of 38 North, said she expects to see at least some clarification of what the negotiated end goal is and sense of time frame for trying to achieve it.
Their appearance comes days before a summit between the real leaders in the city-state. I said maybe in the first minute.
"Singapore chain Wolf Burgers is even offering a "Burger for World Peace" and urged Kim and Trump to "#settlethebeef". The ensuing recognition as a "normal country" could then allow sanctions relief, and later worldwide aid and investment.
President Trump cited the unprecedented nature of the meeting and said he was convinced that Kim wants to do good things for his country.
Giuliani: President Trump Has Constitutional Authority To Pardon Himself
Schumer says, "If he did nothing wrong, President Trump should welcome a thorough investigation to exonerate him". On Tuesday, the Senate's Republican leader , Mitch McConnell, also discouraged talk of a self-pardon by Trump.
Notably, the law imposes restrictions not just on these North Korean entities, but on any companies, banks or other entities that might want to do business with entities controlled by the North Korean government.
It's not clear if he had shipped over the massive bulletproof and fireproof limousine that became a social media sensation when Kim was shown being driven across the border between the Koreas during his first summit with South Korean President Moon Jae-in, in April, with a dozen staunch bodyguards encircling the auto.
Trump hopes to persuade Kim to completely abandon the arsenal of nuclear weapons and ballistic missiles that the North Koreans have spent more than a generation amassing. "This should be a matter between US and South Korea".
Kim has the "opportunity the likes of which, almost, if you look into history, very few people have ever had", Trump said. We really think that North Korea will be a tremendous place in a very short period of time.
He added, "If they retaliate they are making a tremendous mistake". China - North Korea's only ally - has long pushed for dialogue between Washington and Pyongyang. "My experience is that Americans sometimes don't recognise progress when they see it from the North Koreans, and thus may miss openings". "I felt as if I was back in time, back in the period immediately after the Second World War when worldwide military tribunals and other investigations were conducted into the Nazi horrors". I think it would be good for the world. "I think that Chairman Kim Jong Un is prepared to do that as well", he said. "We figured if the United States was attacked, we would have to keep order". The Iran nuclear deal, on the other hand, was an executive agreement negotiated under the Obama administration.
They'll arrive to "summit fever" across the island territory - with locals selling everything from drinks and tacos to gold medallions to mark Trump's historic huddle with the hermit king.
"This being said, a treaty is not ironclad and usually contains clauses that allow each side to withdraw from the treaty", Aum said. North and South Korea are technically still at war, 68 years later.