State Department envoy Stephen Bosworth met Saturday with South Korean nuclear envoy Wi Sung-lac and was to meet Sunday with South Korean Foreign Minister Yu Myung-hwan, Yonhap news agency reported.
Bosworth, who visited China Friday and was to visit Japan Monday, sought advice on jump-starting six-nation denuclearization talks with North Korea, Yonhap reported Saturday.
North Korea, which has said it won't rejoin the talks, Friday announced it was close to acquiring technology to enrich uranium for its nuclear arsenal, which North Korea has said contains several plutonium bombs.
U.S. State Department officials have said they doubt North Korea has sufficient facilities to produce enriched uranium, but they are concerned by North Korea's renewed threat, Yonhap reported.
North Korea's announcement Friday followed weeks of conciliatory gestures, including the release of South Korean and U.S. nationals and the reconnection of direct communication lines with South Korea, Yonhap reported.