Press Secretary Sarah Sanders told reporters traveling with Trump on Air Force One that he spoke for around 15 minutes each with Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-in.

"He gave them an update on the meeting," Sanders said. "He told them he will continue the conversation."

The US-North Korea nuclear summit ended abruptly in Hanoi earlier Thursday, with Trump saying he had decided to "walk" in the face of Kim's demands to drop sanctions.

The much-anticipated second meeting between the two leaders was supposed to build on their historic first summit in Singapore, but they failed to sign a joint statement as initially scheduled and the talks ended in deadlock.

Abe earlier said he backed Trump after the talks collapsed.

Tokyo has regarded the US-led diplomatic push with Pyongyang with suspicion, and has sought to keep its interests on the table in the discussions by coordinating closely with its ally Washington.