The U.S. president has called it a "one-time shot" at peace.
Waiters were spotted near an elaborate dining room carrying Diet Cokes.
President Donald Trump has arrived at Singapore's government house for a meeting with the island city-state's leader. On Sunday, as the global media swarmed Singapore and Kim arrived on a special Air China flight, just hours before Trump, there was still no word. U.S. officials were quoted as saying that the two leaders could spend the first two hours alone with translators but not advisors.
His sister and close aide Kim Yo Jong is also in Singapore, and is believed to have travelled separately on the ageing Soviet-made Ilyushin-62 that is Kim's personal aircraft.
Seoul's Unification Ministry says the surveys conducted through home visits, phone calls and letters will continue through August 10.
"I feel confident Kim Jong-un wants to do something great for his people", Trump said, adding that, "he won't have this opportunity again".
If one looks closely, North Korea is been developing nuclear weapons for decades, culminating in the test of a thermonuclear device in 2017. Kim's meeting with Trump comes after Kim's recent meetings with South Korean President Moon Jae-in (jah-YIHN'). Kim Jong Un is not that way.
After a flurry of contacts between the two Koreas, South Korean officials suggested to Trump in March that Kim would be willing to meet face-to-face. The official was not authorized to speak publicly about internal deliberations and insisted on anonymity.
The Trump administration has already said it does not seek "regime change" and has no intention of sending its forces into the country.
By North Korean standards, Monday's announcement actually came a bit earlier than usual.
Trump initially touted the potential for a grand bargain with North Korea to rid itself of a nuclear missile programme that has advanced rapidly to threaten the United States, insisting he would swiftly achieve what previous US administrations have failed to do.
Monday's session was held for 2 hours, with the US Ambassador to the Philippines, Sung Kim, taking part.
The on-off nature of the meeting means Singapore, which was chosen due to its history of holding high-profile summits and because it is seen as a secure location, has had just two full weeks to prepare.
"The success will be in the shutter clicks of the cameras", he said.
But questions remain over Kim's willingness to fully abandon his nuclear program, dismantle weapons and allow independent experts in to verify and inspect every site in the country that might be involved.
It is unclear, however, under what terms North Korea would agree to in an effort to reduce its nuclear arsenal. Trump traveled to Singapore from Canada, where he a meeting with other world leaders.
Earlier on Sunday evening, Trump arrived at Singapore's Paya Lebar Air Base and is now staying at the Shangri-La Hotel.