They are scheduled to meet again in Hanoi, Vietnam, from Feb. 27-28. Their summit is expected to focus on fleshing out Pyongyang's denuclearization steps and Washington's compensation in return.

"Our goal remains the same: to achieve our shared objective of a final, fully verified denuclearization of the DPRK as committed (to) by Chairman Kim in Singapore," Harris said during the forum hosted by the local nonprofit think tank Chey Institute for Advanced Studies. The DPRK is the acronym for the North's official name, the Democratic People's Republic of Korea.

"The United States and our South Korean ally are in complete agreement that sanctions will remain until DPRK denuclearizes," he added.

In the Singapore summit, Kim agreed to work toward the "complete denuclearization" of the Korean Peninsula but with little clarity on how to achieve that long-elusive goal.

The North has demanded the US's "corresponding measures" in return for its additional denuclearization steps, which may include partial sanctions relief, humanitarian aid, the establishment of a US liaison office in Pyongyang and the declaration of a formal end to the 1950-53 Korean War.

But the US has been adamant in its demand for the North's concrete, substantive steps toward its nuclear disarmament, such as a full declaration of its nuclear and missile programs.

Apparently emphasizing Beijing's role in keeping anti-Pyongyang sanctions, Harris said, "Without China's support on sanctions, we wouldn't have achieved (the) progress that we have made so far."

Harris also used his speech to promote Washington's policy for a "free, open" Indo-Pacific.

"Developments on the Korean Peninsula are an important part of the US commitment to a free, open Indo-Pacific. This is not just the US's interests but in all of our nations' strategic interests," he said.

"When we say open, we want all nations to enjoy open access to the seas and airways. And we want a peaceful resolution of territorial and maritime disputes, key to international peace," he added. (Yonhap)