The US says its discussions with North Korea are moving “more quickly than expected” ahead of the summit in Singapore on Tuesday.
The preliminary talks between officials have been taking place ahead of the unprecedented first meeting.
Mr Trump had been scheduled to fly back to Washington on Wednesday morning after spending Tuesday with the North Korean leader in Singapore.
The White House also confirms that President Donald Trump and Kim Jong-un will hold a one-on-one meeting, with only translator’s present.
The outcome may determine the fate of North Korea’s nuclear program.
The US insists it will accept nothing less than complete denuclearization of the Korean peninsula.
North Korea has said it is willing to commit to denuclearization, but that term is open to interpretation.
It is also unclear what concessions Pyongyang could demand in return – which makes the summit very hard to predict, according to analysts.
The night before the big day
As night closed in, Mr Kim has made a rare tour of some city sights. He waved at spectators who cheered as he arrived to visit a high-end hotel.
Singapore’s Foreign Minister Vivian Balakrishnan also tweeted a picture of them going “jalan-jalan”, a local term meaning to go out for a walk, in the Gardens by the Bay park.
— Vivian Balakrishnan (@VivianBala) June 11, 2018
He and Mr Trump are staying in separate hotels, not far from each other. Security is a high across the area.
The two leaders will meet on Tuesday at a hotel on Sentosa, a popular tourist island a few hundred metres off the main island of Singapore.
Both leaders ‘supremely confident’
Mr Balakrishnan, who met Mr Trump and Mr Kim separately on Sunday evening, told the BBC that both leaders were feeling “supremely confident”.
Mr Trump has said he has a “good feeling” about Tuesday’s much-anticipated summit.
Great to be in Singapore, excitement in the air!
— Donald J. Trump (@realDonaldTrump) June 11, 2018
What is the agenda?
According to the White House, this is the plan for the summit:
Mr Trump and Mr Kim initial greetings (9am local time)
Expanded meeting with other representatives
Mr Trump will leave the country that same evening to return to the US.
What has North Korea said?
Highly unusually, North Korea’s state-run media are already reporting on Mr Kim’s trip to Singapore to meet Mr Trump. As a rule, they would only report on the leader’s movements after the event.
An editorial in the Rodong Sinmun news outlet also talked about a “new relationship” with the US.