Kim smiled as he took a selfie with Singapore's Foreign Minister Vivian Balakrishnan at the scenic waterfront Gardens by the Bay. Shortly after arriving, Kim visited with Singapore Prime Minister Lee Hsien Loong, who is scheduled to meet with Trump on Monday.
Though Trump has been criticized for his failure to demand more concessions from North Korea before agreeing to a face-to-face meeting, which experts say gives Kim the sort of legitimacy on the global stage he desires, downplaying expectations does two things.
The summit will be the first meeting between Trump and Kim and mark a turnaround of relations between the two leaders after a long-running exchange of furious threats and insults.
The summit - the first ever between a sitting American president and North Korea's leader - was to kick off at 9 a.m., the White House said.
The daylong summit will also include a working lunch and a larger meeting involving aides to both leaders, the White House said.
Kim Jong Un, center, tours the Esplanade in Singapore on Monday during a surprise late-night tour. It is believed that Trump and Kim will begin with a two-hour one-on-one session with translators, before an expanded meeting that includes advisers.
According to FlightRadar24, a website that tracks the flights of various aircraft, thousands of people followed the progress of Kim Jong-un's plane.
Despite the initial high stakes of a meeting meant to rid North Korea of its nuclear weapons, the talks have been portrayed by Trump in recent days more as a get-to-know meeting.
"Our eyes are wide open with respect to the risks, but it is our fervent hope that chairman Kim wants to make a strategic change", he said.
The United States is willing to offer North Korea "unique" security guarantees if it embarks on "complete verifiable and irreversible denuclearization", Secretary of State Mike Pompeo said Monday. "You would start at least a dialogue, because, you know, as a deal person, I have done very well with deals". Mr Kim is reported to be flying out even earlier, at 2pm local time.
Trump, after the first-ever meeting between USA and North Korean leaders, had been scheduled to fly back to Washington on Wednesday morning after spending Tuesday with Kim in Singapore. India, Pakistan and North Korea are not CTBT signatories. While Kim is staying at the St Regis Hotel that has been converted into a fortress ahead of June 12, Trump is reportedly staying at Shangri-La Hotel.
Larry Kudlow, Trump's economic adviser, said Sunday on CNN that Trudeau's criticism had damaged Trump's prestige before the summit - and that's why Trump reacted so strongly.
Plans for the meeting almost foundered after Trump abruptly withdrew in May, citing North Korea's "open hostility" during negotiations.
"He's one of the best negotiators of all time and I'm looking forward to him adding to his historic success at the Singapore Summit", Rodman wrote.