Kim met Singapore Prime Minister Lee Hsien Loong shortly after his arrival, driving from the St. Regis Hotel where he is staying, through the famous Orchard Road shopping district, which was closed off for his tightly guarded motorcade.
Bodyguards in dark suits jogged alongside his limousine. At the hotel lobby, grim-faced North Korean security guards warned other hotel guests not to take pictures as Kim walked to his Mercedes Benz limousine.
When a couple of guests took a picture, a North Korean official stormed up to them, demanding to check their phones.
"I saw them taking a photo of our chairman. How dare they do so, they shouldn't," the official told Reuters later. He declined to be identified. Under the watchful eye of the official, and St. Regis staff, one male guest deleted his photos.
In his first public comments since arriving, Kim said Singapore's role would be recorded in history if the summit was a success.
Trump, who is staying in a separate hotel, the Shangri-La, is due to meet Lee on Monday.
North Korea spent decades developing nuclear weapons, culminating in the test of a thermonuclear device in 2017. It also successfully tested missiles that can reach the US mainland.
The tests came amid a campaign of "maximum pressure" on North Korea, led by the United States, that tightened economic sanctions and the possibility of military action.
The two leaders exchanged insults as fears of war grew.
But then in a New Year's address, Kim sounded a conciliatory note, saying his country had completed development of its nuclear programme and would focus on economic development.
He also suggested a meeting with South Korea.
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 and the U.S. president agreed.
Many experts on North Korea, one of the most insular and unpredictable countries in the world, remain sceptical Kim will ever completely abandon its cherished nuclear weapons. They believe Kim's latest engagement is aimed at getting the United States to ease the crippling sanctions that have squeezed the impoverished country.
Believed to be 34, Kim is one of the youngest heads of state in the world and looks an unlikely candidate to be making history of the kind that has eluded his father and grandfather, both past leaders of North Korea.
But since taking power after his father's death, the youthful Kim has displayed a mixture of ruthlessness, pragmatism and statecraft to get this prize: to sit across the table with the leader of the United States and be treated as an equal.
For Trump, a successful summit will give him a win on the international stage.
While foreign policy isn't usually a major aspect of congressional elections, it is unclear if Trump’s focus on getting tough with trade partners and solving the North Korean nuclear issue will have some influence on voters in the mid-term polls in November.
The two leaders meet at 9 a.m. (0100 GMT) on Tuesday at the Capella on Sentosa island, a refurbished British Army artillery mess that is one of Singapore's most expensive hotels.
Two S Korean media staff deported
Two South Korean media staff have been deported after being arrested for illegally entering the North Korean ambassador's residence in Singapore, police said on Sunday. Some 3,000 journalists have descended on Singapore for the historic summit between US President Donald Trump and North Korean leader Kim Jong Un on Tuesday. - AFP/PTI