US President Donald Trump tours the Demilitarized Zone dividing the two Koreas

Highlights Trump will visit the Demilitarized Zone dividing the two Koreas on Sunday

Trump had turned to Twitter to invite Kim Jong Un to a third meeting

Trump had previously met Kim Jong Un in Singapore and Hanoi

US President Donald Trump arrived Sunday in the Demilitarized Zone dividing the Korean peninsula ahead of a meeting with the North's leader, Kim Jong Un.

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

Accompanied by South Korean President Moon Jae-in, an earnest-looking Trump toured an observation post overlooking North Korean territory, with a US military officer pointing out the sights.

US President Donald Trump toured an observation post overlooking North Korean territory in his Marine One helicopter

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.

"There was great conflict here prior to our meeting in Singapore," Trump said at the observation post.

"After our first summit, all of the danger went away... It's all working out, it always works out," he concluded before leaving the site to meet with US troops.

After some very important meetings, including my meeting with President Xi of China, I will be leaving Japan for South Korea (with President Moon). While there, if Chairman Kim of North Korea sees this, I would meet him at the Border/DMZ just to shake his hand and say Hello(?)! - Donald J. Trump (@realDonaldTrump) June 28, 2019

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