he 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.
The White House also confirms that President Donald Trump and Kim Jong-un will hold a one-on-one meeting, with only translators present.
The outcome may determine the fate of North Korea's nuclear programme.
The US insists it will accept nothing less than complete denuclearisation of the Korean peninsula.
North Korea has said it is willing to commit to denuclearisation, 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.
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.
Earlier in the day, Mr Trump had lunch with Singapore's President Lee Hsien Loong and was presented with a cake ahead of his birthday on Thursday.
Mr Kim and Mr Trump are staying in separate hotels, not far from each other. Security is 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.
Mr Trump has said he has a "good feeling" about Tuesday's much-anticipated summit.
The preliminary talks between officials have been taking place ahead of the unprecedented first meeting.
The White House also confirms that President Donald Trump and Kim Jong-un will hold a one-on-one meeting, with only translators present.
The outcome may determine the fate of North Korea's nuclear programme.
The US insists it will accept nothing less than complete denuclearisation of the Korean peninsula.
North Korea has said it is willing to commit to denuclearisation, 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 made a 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.
Mr Kim and Mr Trump are staying in separate hotels, not far from each other. Security is 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.
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Mr Trump has said he has a "good feeling" about Tuesday's much-anticipated summit.
