Stephen Bosworth made no comment on his arrival in Beijing on Wednesday night, and the U.S. Embassy said he was to meet Thursday with Vice Foreign Minister Zhang Zhijun and Senior Representative for Korean Peninsula Affairs Wu Dawei. He was expected to travel to Japan later Thursday.

Bosworth is expected to ask China for information on last month's talks in Pyongyang between North Korean leader Kim and Chinese State Councilor Dai Bingguo, Beijing's top foreign policy official. China has come under growing pressure to push North Korea, its close ally, to change its behavior after the communist country shelled a South Korean island late last year, killing four people.

North Korea will be a key issue during Chinese President Hu Jintao's visit to Washington later this month.

Bosworth met Wednesday in Seoul with South Korean officials and said he was hopeful for "serious negotiations" soon on the North.

In Washington on Wednesday, Secretary of State Hillary Rodham Clinton and Chinese Foreign Minister Yang Jiechi held "lengthy discussions" on North Korea and ironed out details of Hu's visit Jan. 19, State Department spokesman P.J. Crowley said.

Crowley said both the United States and China want stability on the Korean peninsula. "Neither one of us wants to see the emergence of a North Korea that is a nuclear state," he said. "We hope that coming out of the visit and the discussions with President Hu Jintao we would have a consensus on the best way to move forward."

Also on Wednesday, North Korea called for "unconditional and early" talks with South Korea to put an end to months of tensions. Seoul quickly dismissed the offer, carried by the North's official Korean Central News Agency, as insincere and said it was waiting for an apology for two deadly attacks blamed on Pyongyang.

Tensions between the two Koreas have been at their highest level in years since North Korea showered artillery on a South Korean-held island near their disputed maritime border in November, killing four South Koreans. The attack was the first on a civilian area since the 1950-53 Korean War, and occurred in waters not far from the spot where a torpedo sank a South Korean warship eight months earlier, killing 46 sailors.

The attack on the warship was also blamed on the North — an allegation the country denies.

But North Korea has made some conciliatory moves recently. On New Year's Day, the government issued a lengthy statement calling for warmer ties and the resumption of joint projects with South Korea. Pyongyang, eager for food and fuel assistance, has said it wants stalled nuclear disarmament talks to restart.

Washington and Seoul have said the North must first fulfill past nuclear disarmament commitments before talks can resume.