"North Korea should act with caution", the spokesman urged, stressing that "the nature of the USA government is not such that one can be optimistic about it".
Larry Kudlow, the White House senior economic adviser, CNN on Sunday Trump is "not going to let a Canadian prime minister push him around" in advance of the North Korean meeting. But Moon has to be present when and if such a document is signed. That armistice has yet to be replaced with a peace treaty, leaving the peninsula in a technical state of war. Trump is probably keen to have a successful summit after disagreements at the G7 summit and before the November mid-term elections in the United States.
Some foreign-policy experts said the breakdown at the Group of 7 meeting would play to North Korea's advantage, since Mr. Trump can ill afford a second failed summit, back to back.
Trump and Kim will first meet one-on-one in a closed session, before a larger meeting with key advisers, USA officials said.
Before signing what Trump described as a "comprehensive" document, Kim said the two leaders had a historic meeting "and chose to leave the past behind".
Kim said through an interpreter: "It wasn't easy for us to come here". But, if that cannot be achieved at a price that South Koreans, Chinese, and the American public can accept, then something like a comprehensive, verifiable cap on North Korea's most risky activities and capabilities would make everyone more secure than the alternatives of war or resumed expansion of North Korea's arsenal.
Hatred of the U.S. is helped by the very real memories among older North Koreans of the brutal bombing campaign waged against their country by the USA during the Korean war, in which hundreds of thousands of civilians were killed and cities leveled between June 1950 and July 1953.
In a statement, the White House said Mr Trump would speak to the media before departing for the USA at 8:00pm.
As the two leaders met, Singapore navy vessels, and air force Apache helicopters patrolled, while fighter jets and an Gulfstream 550 early warning aircraft circled.
Aware that the eyes of the world were on a moment many people never expected to see, Kim said many of those watching would think it was a scene from a "science fiction movie". "Getting a good picture everyone, so we all look nice and handsome and thin.perfect". They then resumed their walk.
Trump responded to that commentary Tuesday on Twitter, saying: "The fact that I am having a meeting is a major loss for the US, say the haters & losers".
It was Kim's only foray on Monday outside of the St. Regis hotel, where he's been staying since his arrival a day earlier.
Kim Jong-Un arrived in Singapore surrounded by smartly dressed men.
Trump responded to such commentary on Twitter, saying: "The fact that I am having a meeting is a major loss for the US, say the haters & losers". But he added "our hostages" are back home and testing, research and launches have stopped.
Discussions would focus on "the issue of building a permanent and durable peace-keeping mechanism on the Korean peninsula, the issue of realising the denuclearisation of the Korean peninsula and other issues of mutual concern", KCNA said.
Shortly afterward, he had a meeting with Singapore's Prime Minister Lee Hsien Loong at the Istana palace, during which he expressed gratitude for providing logistical support for the summit.
Still, the sense of anticipation was great in Singapore, with people lining spotless streets holding cellphones high as Trump headed to meet Lee.
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