North Korean leader Kim Jong Un has landed in Singapore ahead of a summit with US President Donald Trump that could end a nuclear stand-off between the old foes and transform the secretive, impoverished Asian country.
When Trump and Kim meet on the resort island of Sentosa on Tuesday they will be making history even before they start.
Enemies since the 1950-53 Korean War, the leaders of North Korea and the United States have never met previously - or even spoken on the phone.
Kim arrived at Singapore's Changi Airport after his longest trip overseas as head of state wearing his trademark dark Maoist suit and distinctive high cut hairstyle.
He was greeted by Singapore's foreign minister, Vivian Balakrishnan, who posted a picture on Twitter of him shaking hands with Kim and the message: "Welcomed Chairman Kim Jong Un, who has just arrived in Singapore."
Later on Sunday, Kim left the St Regis hotel in central Singapore in a motorcade that included his stretch Mercedes Benz limousine and travelled to the presidential palace, known as the Istana, where he met Prime Minister Lee Hsien Loong.
Kim said Singapore's role would be recorded in history if the summit was a success.
"The entire world is watching this historic summit between Kim Jong Un and the United States of America. Thanks to your sincere efforts ... we were able to complete preparations for the summit," Kim said to Lee through an interpreter.
Lee, in turn, thanked him for the opportunity to hold the summit
Trump is expected to arrive at 8pm local time (2200 AEST) and go straight to his hotel, the Shangri-La, the White House said.
Officials onboard Air Force One include Secretary of State Mike Pompeo, National Security Adviser John Bolton, White House Chief of Staff John Kelly and White House Press Secretary Sarah Sanders.
Authorities have beefed up security around the hotels where Trump and Kim (Saint Regis) will be staying.
At stake at the summit are North Korea's nuclear weapons and peace on the Korean Peninsula. North Korea spent decades developing nuclear weapons, culminating in the test of a thermonuclear device in 2017. It also successfully tested missiles that had enough range to reach the US mainland.
The tests came amid a campaign of "maximum pressure," led by the United States, that tightened economic sanctions against North Korea and raised the possibility of military action.
In a New Year's address, Kim said his country had completed development of its nuclear program and would focus on economic development, suggesting 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.
The summit comes after weeks of sometimes-contentious discussions and was briefly cancelled amid North Korean outrage over messaging from some US advisers.
Many remain sceptical Kim will ever completely abandon his nuclear programs. They believe his latest engagement is aimed at getting the United States to ease crippling economic sanctions that have squeezed the impoverished country.
For Trump, a successful summit will see him achieve badly needed recognition on the international stage ahead of congressional elections in November.
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.
The two leaders meet at 9am (1100 AEST) on Tuesday at the Capella on Sentosa island, a refurbished British Army artillery mess that is now one of Singapore's most expensive luxury hotels.