The Shanghai Cooperation Organization, which groups Russia, China, Kazakhstan, Kyrgyzstan, Uzbekistan and Tajikistan, urged a deadline be set for withdrawal of the foreign forces from its member states in light of what it said was a decline in active fighting in Afghanistan.

The alliance's move appeared to be an attempt to push the United States out of a region that Moscow regards as historically part of its sphere of influence and in which China seeks a dominant role because of its extensive energy resources.

The United States rejected the call for a deadline. State Department spokesman Sean McCormack said the U.S. military presence "is determined by the terms of our bilateral agreements, under which both countries have concluded that there is a benefit to both sides from our activities."

At the Defense Department, spokesman Lawrence Di Rita said that regarding U.S. bases in Uzbekistan, "it's a decision the Uzbek government has to make as to whether or not we would continue to operate from that."

U.S-led military forces have been deployed at air bases in Uzbekistan and Kyrgyzstan since the Sept. 11, 2001, attacks to back up the anti-terrorist campaign in neighboring Afghanistan.

According to the U.S military, Uzbekistan hosts at least 800 U.S. troops, while 1,200 U.S.-led troops are in Kyrgyzstan.

Tajikistan has allowed the French air force to use Dushanbe airport since 2001 as a base for logistical support to its troops in Afghanistan. Some 200 French air force personnel are based there.

"We support and will support the international coalition, which is carrying out an anti-terror campaign in Afghanistan, and we have taken note of the progress made in the effort to stabilize the situation," the SCO said in a declaration at a summit in the Kazakh capital.

"As the active military phase in the anti-terror operation in Afghanistan is nearing completion, the SCO would like the coalition's members to decide on the deadline for the use of the temporary infrastructure and for their military contingents' presence in those countries," it said.

A Kremlin foreign policy adviser, Sergei Prikhodko, said the group had not demanded an immediate withdrawal. But he added it was "important for the SCO members to know when the (U.S.) troops will go home."

The Kremlin did not object when Uzbeks and Kyrgyz agreed to host U.S. troops.

However, Moscow's suspicion of the West has increased recently amid speculation the United States is encouraging the overthrow of Central Asia's pro-Russian authoritarian governments.

Earlier Tuesday, SCO leaders accused unnamed outside forces of trying to destabilize Central Asia.

The summit followed the violently suppressed uprising in eastern Uzbekistan in May and turmoil in Kyrgyzstan in March when demonstrators stormed the administration's offices and sent the president fleeing into exile.

Chinese leader Hu Jintao said at the summit he believed "the fate of Central Asian countries is in their own hands and they are wise and capable enough to sort out their domestic problems on their own."

The leaders vowed to step up security cooperation in the region.

Russian President Vladimir Putin said "new regional threats are of a trans-border nature ... There are people who place orders and execute them. Our task is to find them and render them harmless and also to prevent their activity."

Islam Karimov, the president of Uzbekistan, said some outside forces were joining radical Islamists "to create instability and undermine the region economically in order to impose their own development model."

Uzbekistan was widely denounced abroad for the harsh suppression of the May uprising in the city of Andijan — in which Uzbek authorities say 176 people died but rights activists say as many as 750 may have been killed.

Karimov put restrictions on the U.S air base in Uzbekistan after Washington joined calls by other Western nations for an international probe into the Andijan massacre.

However, Russia and China expressed support for Uzbek authorities at the time.

Iran, India and Pakistan joined the SCO Tuesday as observers. If they become fully fledged members, the group will represent half the world's population.

Russia in particular in recent years has pushed for what it calls a "multipolar" world, seeking to balance alleged U.S. domination of foreign policy issues.