By North Korean standards, Monday's announcement actually came a bit earlier than usual. At the G7 summit in Canada and in the hours afterward, Trump railed against trade practices that he described as unfair and said he'd given USA representatives instructions to rescind an agreement to official communique that outlined a mutual plan to ensure "free, fair, and mutually beneficial trade".
The meeting was Trump's only scheduled public event as White House officials prepared for the critical meeting on Tuesday with Kim. The official was not authorized to speak publicly about internal deliberations and insisted on anonymity.
Up early in Singapore, Trump tweeted with cautious optimism: "Meetings between staffs and representatives are going well and quickly. but in the end, that doesn't matter".
Later, Kim's plane landed at Changi airport. But many say this is unlikely, because the weapons help to guarantee the survival of Kim's government. Kim and Lee also met on Sunday.
The bodyguards were glimpsed flanking Kim's Mercedes-Benz limousine as it traveled to the St. Regis Hotel in Singapore on Sunday. Traffic was held up in the steamy midday sun and scores of bystanders were penned in by police when Trump went to meet Lee.
"It's a huge win for Kim Jong Un, who now - if nothing else - has the prestige and propaganda coup of meeting one on one with the president, while armed with a nuclear deterrent", said Michael Kovrig, a northeast Asia specialist at the International Crisis Group in Washington.
Trump has sought to lower expectations for the summit in recent days, suggesting that it would be the start of a lengthy process to get Pyongyang to begin dismantling its nuclear and ballistic missile programs.
This photo, taken from the North's Rodong Sinmun daily newspaper on June 11, 2018, shows North Korean leader Kim Jong-un inspecting an honor guard in Pyongyang before leaving for Singapore the previous day.
Broad smiles and a firm handshake kicked off the first meeting between Prime Minister Lee Hsien Loong and North Korean leader Kim Jong Un, as Singapore prepares to host a historic summit whose twists and turns have enraptured the world.
The North Korean autocrat's every move will be followed by 3,000 journalists who have converged on Singapore, and by gawkers around the world, up until he shakes hands with Trump on Tuesday.
But while Singapore is well within its range, questions have been raised about its reliability and Kim, it turned out, was not on board.
But it's Kim's pursuit of nuclear weapons that gives his meeting with Trump such high stakes.
In a statement released by the state news agency KCNA, it said the two leaders would discuss a "permanent and durable peace-keeping mechanism" for the Korean Peninsula, the "denuclearisation" of the Korean peninsula and other issues of mutual concern. The session will be expanded to a bilateral meeting and will include advisors.
In his debut speech at the United Nations last September, Trump derided Kim as a "rocket man" on a "suicide mission for himself and for his regime".