Trump lands at demilitarised zone ahead of meeting with North Korea's Kim Jong-un

US President Donald Trump arrived at the demilitarised zone (DMZ) separating the two Koreas on Sunday ahead of his meeting with North Korean leader Kim Jong-un.

The expected encounter, only suggested a day earlier by Trump on Twitter, comes with negotiations over the North's nuclear programme in stalemate since the leaders' last summit in Vietnam in February.

Accompanied by South Korean President Moon Jae-in, an earnest-looking Trump visited a guard post in the northernmost part of the South Korean side of the DMZ, looking into the North, where he will speak with US and South Korean servicemen.

Trump and Kim are expected to meet at the Joint Security Area patrolled by soldiers from both Koreas near the inter-Korean border.

Trump is expected to hold a brief encounter with Kim in the DMZ, which would be their third face-to-face meeting after a historic initial summit in Singapore and a second in Hanoi that collapsed without an agreement.

The two would "just shake hands quickly and say hello because we haven't seen each other since Vietnam", Trump said earlier.