In this June 12, 2018, file photo, U.S. President Donald Trump, right, meets with North Korean leader Kim Jong-un on Sentosa Island, in Singapore. AP

South Korea and the United States agreed Thursday to coordinate closely on possible inter-Korean projects amid stalled nuclear talks between Washington and Pyongyang, Seoul's chief nuclear envoy said Thursday.

Lee Do-hoon, special representative for Korean Peninsula peace and security affairs, made the remark to reporters after holding talks with his U.S. counterpart, Deputy Secretary of State Stephen Biegun, in Washington.

The pair met after President Moon Jae-in expressed a desire earlier this week to implement inter-Korean projects as a way to facilitate denuclearization negotiations between the North and the U.S. Most of the projects, including efforts to reconnect railways and roads between the Koreas, have stalled due to United Nations sanctions on Pyongyang.

"(Biegun) and I agreed that from now on, South Korea and the U.S. will continue to hold close consultations on inter-Korean cooperation projects. We are just beginning," Lee told reporters outside the State Department.

Washington has been wary of allowing exceptions to the U.N. sanctions regime out of concern they could undermine its "maximum pressure" campaign to denuclearize the North.