The two sides have been trying to agree on the next steps for fulfilling the commitments made at their first summit in Singapore in June, which included complete denuclearization and the building of a lasting peace mechanism on the Korean Peninsula.

"We're looking forward to a very good summit," State Department deputy spokesperson Robert Palladino said at a regular press briefing.

"I'm not going to get ahead of the summit and the agenda for the summit, but we're very much focused on setting it up," he added when asked for details, including the exact city that will host the summit and whether the US is ready to declare a formal end to the 1950-53 Korean War as a concession to the North.

He noted that sanctions on North Korea will remain until denuclearization is complete.

The spokesman also thanked Vietnam for hosting the event.

"The history of our two nations reflects the possibilities for peace and prosperity," he said. "We moved past conflict and division towards the thriving partnership that we enjoy today."

Vietnam has been viewed as an instructive model for the North to follow as a former US adversary-turned-major partner. (Yonhap)