U.S. Ambassador to South Korea Harry Harris said on Thursday that the United States "remains open" to engaging with North Korea in advancing negotiations on the North's denuclearization. 

Harris made the remark in a keynote speech for a virtual seminar hosted by the Center for Strategic and International Studies and the Korea Foundation.

The U.S. top envoy said the U.S. remains open to progress through diplomacy on the goals that the leaders of the United States and North Korea set at the historic Singapore Summit.

Harris said he has been following the recent activity in North Korea's border city of Gaeseong and the "choice words" from Pyongyang.

He then reaffirmed that the U.S. remains in close coordination with its ally, South Korea, on efforts to engage North Korea and fully supports Seoul's efforts on inter-Korean relations. He then urged North Korea to refrain from further counterproductive actions.