The two leaders, who met for the first time in Singapore last June, are due to hold talks in the Vietnamese capital Hanoi on February 27-28.

Trump is seeking to persuade the North Korean leader to abandon his nuclear arsenal.

A US officials said next week's meeting would be "similar in format to what we saw last June in Singapore... there will be an opportunity for the two leaders to see one another one-on-one" before holding meetings with their respective teams.

Stephen Biegun, the US special envoy to Pyongyang, is already in Hanoi holding talks with his North Korean counterpart Kim Hyok Chol.

US officials have declined to speculate on what elements might be included in a joint statement at the end of the meeting.

On Wednesday, Trump again praised his relationship with the North Korean leader but said he would have to make a "meaningful" gesture on the nuclear front if he wants to see sanctions lifted.