The Trump administration's special envoy for North Korea is heading to South Korea this week amid growing uncertainty over the future of direct talks between Washington and Pyongyang, the State Department said Tuesday.

Stephen Biegun will visit Seoul on Wednesday and Thursday for meetings with senior South Korean officials on the status of negotiations with the North over getting rid of its nuclear weapons, the department said in a brief statement. It said the discussions would focus "on our shared objective of the final, fully verified denuclearization" of North Korea as well as joint North-South cooperation projects that might help achieve that goal.

The statement gave no indication that Biegun would travel anywhere other than South Korea or meet with officials from North Korea, which has not yet officially named a counterpart for him.

Talks between the U.S. and North Korea have been stalled for months with the two sides at an impasse over next steps following the historic June summit between President Donald Trump and North Korean leader Kim Jong Un and several trips to Pyongyang by Secretary of State Mike Pompeo. Despite no signs of tangible progress, the U.S. insists that plans for a second Trump-Kim summit is still in the works for early next year.

The U.S. wants the North to provide a detailed accounting of facilities that would be inspected and dismantled under a deal while the North is insisting that sanctions be lifted first. In the meantime, several reports from private analysts have accused the North of continuing nuclear and missile development, citing details from commercial satellite imagery.

On Monday, North Korea reacted angrily to a U.S.-supported U.N. General Assembly resolution condemning it for "systematic, widespread and gross violations of human rights" and devoting scarce resources into pursing nuclear weapons and ballistic missiles over the welfare of its people.

That came a day after North Korea marked the seventh anniversary of Kim's father, Kim Jong Il, and slammed the United States for "slander" and "sheer malice" for dragging its feet on efforts to improve relations after the June summit in Singapore.

But the commentary run by the official Korean Central News Agency, deliberately focused its criticism on the State Department and administration officials, not at Trump, and suggested that Pyongyang remains open to another summit.