North Korean leader Kim Jong-un has arrived in Singapore for his scheduled summit meeting with US President Donald Trump.

The historic meeting between the two leaders will take place at the island resort of Sentosa on Tuesday.

It is the first time a North Korean leader has met a sitting US president.

Before setting off, Trump described the summit as a "one-time shot" at peace and said the two were in "unknown territory in the truest sense".

Singapore's minister for foreign affairs Vivian Balakrishnan tweeted a photo of Kim after he touched down in the island nation.

Washington hopes the summit will kick-start a process that eventually sees Kim give up his nuclear weapons.

The two leaders have had an extraordinary up-and-down relationship over the past 18 months, trading insults and threatening war before abruptly changing tack and moving towards a face-to-face meeting.

Both leaders will meet Singapore's Prime Minister Lee Hsien Loong before their summit. (BBC)