A United States delegation led by Deputy Secretary of State James Steinberg arrived in Beijing on Wednesday afternoon to discuss the regional tensions between the two Koreas.
Steinberg is reportedly to meet State Councilor Dai Bingguo, who recently traveled to two Koreas, on Thursday.
There is as yet no further confirmed information about his schedule.
He will stay in the Chinese capital until Friday and then fly to Tokyo.
The Asia visit follows a meeting in Washington between the foreign ministers of the US and its two Asian allies, and comes only weeks before President Hu Jintao visits the United States in January.
A flurry of diplomatic efforts among the six parties involved in the stalled nuclear talks are under way to defuse the regional tensions.
US Governor of New Mexico Bill Richardson was also on his way to Pyongyang as an unofficial envoy.?
Just a day before Steinberg's departure, Mike Mullen, chairman of the US Joint Chiefs of Staff warned of a war on the Korean Peninsula.
On Wednesday the citizens of Republic of Korea (ROK) stopped their cars, donned gas masks and ducked into underground shelters in the country's biggest-ever evacuation drill - a government attempt to prepare traditionally indifferent citizens for possible attacks by the Democratic People's Republic of Korea (DPRK).
Fears of war on the Korean Peninsula have intensified since the two Koreas fired artillery shells at each other last month. Both ROK and DPRK accuse each other of staging the first provocation.
The DPRK on Tuesday accused the ROK of trying to ignite an all-out war, saying Seoul's holding of joint exercise with Washington and firing exercises at 29 venues have worsened the situation.
The nationwide 20-minute evacuation drills in ROK on Wednesday were the largest since the country began the training in 1975.
"Unlike military drills, an evacuation drill is meant to test the ability of civilian units in response to military actions under the state of war, " said Ye Hailin, a military expert from the Chinese Academy of Social Sciences.
Through large-scale evacuation drills mobilization, the ROK government is seeking to accomplish two goals in a single stroke.
"The ROK government is trying to deliver the message that it is well-prepared in the face of an emergency and potential wars, and is capable of avoiding large-scale casualties and loss of control," Ye said.
At the same time, Ye said, the ROK also has an interest in maintaining the current tensions that hang over the Korean Peninsula and to "continue its tough stance towards Pyongyang", Ye said.