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, BBC reported on Monday.
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.
As night closed in, 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.