Kim and Trump shook hands and smiled briefly in front of a row of their national flags at the Metropole hotel in the Vietnamese capital, Hanoi, before heading to dinner together.

Trump told reporters he thought the talks would be very successful, and asked if he was "walking back" on denuclearisation, said "no".

At their historic first summit in Singapore last June, Trump and Kim pledged to work toward denuclearisation and permanent peace on the Korean peninsula but little progress has been made.

Kim said they had overcome obstacles to hold their second summit and praised Trump for his "courageous decision" to begin a dialogue.

"Now that we're meeting here again like this, I'm confident that there will be an excellent outcome that everyone welcomes, and I'll do my best to make it happen," Kim said.

Trump and Kim held a 20-minute, one-on-one chat before sitting down to dinner with U.S. Secretary of State Mike Pompeo Trump's acting Chief of Staff Mick Mulvaney, Kim's top envoy, Kim Yong Chol, and North Korean Foreign Minister Ri Yong Ho.

On Thursday, the two leaders will hold a series of meetings, the White House said. The venue has not been announced.

"We’re going to have a very busy day tomorrow ... Probably a very quick dinner,” said a smiling, relaxed looking Trump, seated beside Kim at a round table with the other four officials and two interpreters.

"Our relationship is a very special relationship."

Kim Jong Un also appeared at ease. “We’ll have a very interesting dialogue,” he told Trump.

REUTERS