The United States was in February given six months to withdraw from the Manas airbase near the Kyrgyz capital of Bishkek, which has played a major role in NATO operations in Afghanistan.
"I don't think the pullout of the base from Manas will drastically impact on the state of security in Central Asia," Nikolai Bordyuzha, general secretary of the Collective Security Treaty Organization, said in an interview with RIA Novosti.
The CSTO comprises Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia, Uzbekistan and Tajikistan.
He added that the U.S. airbase in Kyrgyzstan "was designed to help transport military and non-military cargos to Afghanistan" but now "agreements on the transit of non-military cargoes to Afghanistan have been signed with Russia, Kazakhstan, and Uzbekistan."
He also said the Russian airbase in Kant, Kyrgyzstan, should be augmented and upgraded to perform its missions more effectively.
The Kant base is intended to provide air cover for possible operations by CSTO joint forces in Central Asia.
"As the collective rapid-reaction forces are expanded, the base should become more powerful both qualitatively and quantitatively," he said.
He said Russian authorities had plans, in particular, to increase the number of warplanes deployed at Kant.
Kyrgyz President Kurmanbek Bakiyev signed a decree to close the Manas airbase on February 20. Kyrgyzstan officially notified Washington about the termination of the agreement on a U.S. military presence at the base, and gave it 180 days to withdraw some 1,200 personnel, aircraft and other equipment.
Earlier this month, the president signed a law ending the deployment of all foreign military contingents at the Manas airbase.
The law, which terminates agreements with Australia, Denmark, Italy, Spain, South Korea, the Netherlands, Norway, New Zealand, Poland, Turkey and France, was passed by an overwhelming majority in parliament on March 6.
The base, staffed mainly by U.S. Air Force personnel, has been used since 2001 to support NATO operations in nearby Afghanistan.