"I'd like to see ultimately denuclearization of North Korea," he told reporters, just over a week out from the February 27-28 summit in Hanoi, Vietnam.

"I think that North Korea and Chairman Kim have some very positive things in mind and we'll soon find out, but I'm in no rush," he said, adding that sanctions were continuing in the meantime.

"I hope that positive things are going to happen. I think it'll be a very exciting couple of days."

At their landmark summit in Singapore last year, the mercurial US and North Korean leaders produced a vaguely worded document in which Kim pledged to work toward "the denuclearization of the Korean peninsula."

But progress has since stalled, with the two sides disagreeing over what that means.

Trump, who spoke on Tuesday with his South Korean counterpart Moon Jae-in, said he would do the same on Wednesday with Japanese Prime Minister Shinzo Abe.

A State Department statement meanwhile said the US Special Representative for North Korea Stephen Biegun was traveling to Hanoi in preparation for the summit.