Bishkek, Kyrgyzstan ? American troops can stay at a Kyrgyz air base for as long as they are needed to bring stability to Afghanistan, officials of this former Soviet republic assured Defense Secretary Donald H. Rumsfeld on Tuesday.

The remarks came at a time when the future of the U.S. military presence here and elsewhere in Central Asia has come into question. A July 5 statement by members of the Shanghai Cooperation Organization – of which Kyrgyzstan is a member – called for a timetable for eventual U.S. withdrawal.

Maj. Gen. Ismail Isakov, the acting Kyrgyz defense minister, told reporters after Rumsfeld met with him and newly elected President Kurmanbek Bakiyev that eventually the time would arrive for a U.S. exit.

“Once there is stabilization there will be no need. But now I agree with Mr. Secretary, who mentioned that the situation in Afghanistan is far from stable,” he said.

Rumsfeld did not say publicly what the United States might offer in exchange. But Kyrgyz Foreign Minister Roza Otunbayeva told reporters that the defense secretary had pledged increased military assistance.

About 1,000 U.S. troops use a portion of Kyrgyzstan’s Manas International Airport as a base for air transport and refueling missions to support military and humanitarian operations in Afghanistan. The Pentagon pays about $50 million a year from the arrangement, including fuel sales and landing fees.

Later, Rumsfeld flew to Tajikistan and thanked the government for its partnership with Washington in the global war on terrorism.

No U.S. troops are based in Tajikistan, but U.S. aircraft use Tajik airspace for Afghan-related missions.