A senior American diplomat warned Monday against interference by Russia and China in the political affairs of ex-Soviet Central Asia, where the US military has a base seen as an irritant to Moscow, AP reported.

US Assistant Secretary of State Richard Boucher said the air base in Kyrgyzstan was "a bilateral question between the United States and Kyrgyzstan, not an issue for discussion between the Shanghai Cooperation Organization" - a regional grouping dominated by Russia and China.

The United States set up the base in Kyrgyzstan and one in neighboring Uzbekistan after the September 2001 terror attacks, to back operations in Afghanistan. Uzbekistan kicked the US troops out in 2005 after Washington condemned a bloody government crackdown that rights groups say killed hundreds of civilians.

Earlier that year, the Shanghai Cooperation Organization called for the closure of both bases.

"The countries of the region, Kyrgyzstan, Tajikistan and Uzbekistan and others, they make their own decisions about cooperation with foreign governments and foreign military," Boucher said during a visit to the Kyrgyz capital Bishkek.

"They do not need other countries from outside telling them what to do," Boucher told reporters.

Kyrgyz politicians have recently been calling for the closure of the Manas Air Base, located at the civilian airport near Bishkek, accusing US military personnel of behaving with impunity and citing environmental concerns. Several lawmakers have said they will initiate a bill calling for the base’s closure.

Earlier this month several dozen activists rallied in front of the US Embassy in Bishkek to call for the closure of the base.

Last year, President Kurmanbek Bakiyev threatened to evict US forces unless Washington agreed to significantly boost the amount it pays for the base. The status of the base has also been tainted by the shooting of a Kyrgyz driver by a US servicemen in December, allegedly after the driver threatened the airman with a knife. Co-workers of the slain man said US airmen did not treat them with respect.