"I think we're really going to do something that's going to be very important, but we're not playing the time game", Trump told reporters in NY, responding to a question at a news conference. If takes two years three years, or five months.
"I got all the time in the world [and] don't have to rush it", Trump told the press conference, held at the sidelines of United Nations General Assembly.
His visit to Pyongyang next month will be his fourth this year.
Secretary of State Mike Pompeo listens as President Trump speaks during a U.N. Security Council meeting on September 26, 2018.
Also Wednesday, Russian Foreign Minister Sergey Lavrov warned that dismantling an Iran nuclear accord would threaten global efforts to halt North Korea's nuclear program. The trip will focus on laying a foundation for a successful summit, the official said, and creating a basis for more negotiations.
It was a stark reversal from a year ago, when Mr. Trump made global headlines at the annual gathering of world leaders in NY by deriding Mr. Kim as "Rocket Man" and threatening to "totally destroy" North Korea after a string of provocative missile and weapons tests.
But it was the North Korea issue that took center stage Monday as a mob of security swarmed the lavish hallways of the Lotte New York Palace Hotel in midtown Manhattan, where Mr. Trump and his top foreign policy advisers - including Mr. Pompeo, National Security Adviser John R. Bolton and Vice President Mike Pence - met with South Korean President Moon Jae-in.
"Many things are happening behind the scenes away from the media which nobody knows, but they are happening nevertheless and they are happening in a very positive way".
"I hope bold steps for denuclearization will be taken by related countries in the future and that they will lead to a declaration of the war's end", Moon told the UN General Assembly.
The talks between Trump and Kim would aim to reach agreement on specific denuclearisation steps before moving on to the declaration, observers said.
"Yes, I am a deal guy".
He said the United States accused "some nations" of violating sanctions, including through illegal ship-to-ship transfer of oil to North Korean tankers at sea.
"Much work remains, but we will continue to move forward", Pompeo said. It doesn't look like that any more. -South Korea free trade agreement, which Mr. Trump called a "basic redoing" of what had been "a very unfair agreement for the United States".
Trump argued he had made no concessions to North Korea by engaging in diplomacy, and he defended his decision to suspend joint military exercises with South Korea as a cost-saving measure that benefited the United States. "We will begin removing conflicts in Northeast Asia, starting from the Korean Peninsula", he added. "We're going to deliver on this commitment (to denuclearize) that Chairman Kim has made to the world". But to set a date certain for North Korean denuclearization "would be foolish", according to Pompeo who stated he expects to go again to Pyongyang to arrange a second summit.