China's top official for the long-stalled six-party North Korean nuclear talks has arrived in Pyongyang.
The North's official Korean Central News Agency says Wu Dawei landed Monday, but did not provide further details.
China, which is North Korea's closest ally, has begun to express impatience with Pyongyang, and agreed to a tightening of U.N. sanctions following a North Korean nuclear test this year.
Wu's trip follows his talks with U.S. officials in Washington last week.
The visit also comes as the U.S. is preparing to host South Korean and Japanese officials for talks Wednesday on North Korea's nuclear program.
North Korea, which pulled out of six party-talks in 2009, has called for their resumption with no preconditions. Washington says North Korea needs to show it is serious about abandoning its pursuit of nuclear weapons before the United States will resume negotiations.
Six-party talks over Pyongyang's nuclear program, started in 2003, included the United States, South Korea, Japan, China, Russia and North Korea.