SEOUL: A top North Korean nuclear envoy wants to visit the United States for rare talks next month, news reports said Saturday, amid a push by diplomats to revive negotiations on ending Pyongyang's nuclear program. Officials in Washington said no such trip was planned.

North Korea is strongly pushing for Kim Kye Gwan's trip to the United States in March, but the U.S. has not authorized a visa for him, South Korea's Dong-a Ilbo newspaper reported, citing unidentified diplomatic sources.

Kim told his Chinese counterpart during this week's meetings in Beijing he hopes to hold a bilateral meeting with the U.S. in March, Seoul's JoongAng Ilbo newspaper reported, also citing unnamed diplomats.

Kim left for Pyongyang Saturday after concluding a five-day trip to China, Yonhap news agency reported from Beijing.

"Both sides had an in-depth discussion on the issue of boosting the (North Korea)-China relations and matters of speeding up the denuclearization of the peninsula," the North's Foreign Ministry said in comments carried by its official Korean Central News Agency.

U.S. State Department spokesman P.J. Crowley told reporters Friday there were no plans for a visit by Kim, and no current U.S. discussions with North Korea about such a trip.

Crowley said U.S. officials haven't ruled out future meetings with the North Koreans, but "we believe firmly that the next meeting that U.S. representatives and others should have with North Korea is through a formal six-party meeting."

A bilateral meeting between the North Korean envoy and U.S. officials would be a strong sign that the push to get the disarmament talks back on track was gaining traction. It would also confirm a warming in relations between the U.S. and North Korea, wartime rivals that do not have diplomatic relations.

North Korea, believed to have enough weaponized plutonium for at least half a dozen atomic bombs, walked away from disarmament-for-aid negotiations last year during a standoff over its nuclear and missile programs.

However, after tightened sanctions and financial isolation, the impoverished nation has reached out to Washington, Seoul and Beijing in recent months.

Associated Press writers Hyung-jin Kim in Seoul, Alexa Olesen in Beijing and Edith M. Lederer at the United Nations contributed to this report.