Chinese Premier Wen Jiabao flew to Moscow on Wednesday for a meeting of the Shanghai Cooperation Organization, a security grouping of Central Asian nations led by China and Russia, state media reported.
The group also includes Uzbekistan, Tajikistan, Kyrgyzstan and Kazakhstan. Its aim is to combat separatism and Islamic extremism in Central Asia.
The group called on the United States in July to set a timetable for withdrawing its forces from bases in Central Asia a move reflecting the growing unease Moscow and Beijing feel about the U.S. presence in the strategically placed, resource-rich region.
A short time later Uzbekistan ordered all American troops to leave its Karshi-Khanabad air base.
Wen is visiting Moscow at the invitation of Russian Prime Minister Mikhail Fradkov, the official Xinhua News Agency said.
The agency said Wen's delegation includes security and foreign affairs officials as well as Commerce Minister Bo Xilai, an indication of China's business interests in the area.
U.S. Defense Secretary Donald H. Rumsfeld, in a visit to Beijing last week, spoke of Washington's irritation with what he called China's "seeming preference" for organizations in the Asia-Pacific region that exclude the United States specifically citing the Shanghai Cooperation Organization, reports the AP.