* Russia denies link between aid and closure plan

* Tough challenge for Obama administration

* Uzbekistan considered an option

By David Morgan

WASHINGTON, Feb 5 (Reuters) - The United States said it was still in talks with Kyrgyzstan on Thursday about retaining an important air base there but predicted U.S. and NATO operations in neighboring Afghanistan would not be affected if it closed.

Kyrgyz President Kurmanbek Bakiyev announced this week the closing of the Manas air base after securing a $2 billion aid package from Russia. Kyrgyzstan's parliament will vote next week on whether to close the a major hub for troops and cargo flowing into Afghanistan. ID:nL5661075

"It is regrettable that this is under consideration by the government of Kyrgyzstan," Secretary of State Hillary Clinton told reporters. ID:nN05386343

"We will proceed in a very effective manner no matter what the outcome of the Kyrgyzstan government's deliberations might be," Clinton said of military operations in Afghanistan.

Western experts believe Russia, irked by the U.S. military presence in its former sphere of influence, could hope to use the base as a bargaining chip in a complex power game that also involves NATO expansion in Eastern Europe and U.S. plans for a European missile shield.

Moscow denies any link between the aid and closure plan.

The move poses a tough challenge for U.S. President Barack Obama as he considers proposals to send thousands of extra U.S. troops to Afghanistan to combat an intensifying insurgency by the Taliban and other militant groups.

"It looks like this really is a commitment to close the base. If that's the case, it ends up leaving the U.S. and NATO at the whim of cooperation with Russia," said Cory Welt, a Eurasian studies expert at Georgetown University in Washington.

'VERY MUCH ENGAGED'

Pentagon and State Department officials said the United States remained in talks with Kyrgyzstan about the base.

"We're still very much engaged," Pentagon spokesman Bryan Whitman told reporters. ID:nN05370295

The United States has 36,000 troops in Afghanistan, including 17,000 who operate as part of a 50,000-strong NATO force.

Washington pays the Kyrgyz government $17.4 million a year to use Manas as a supply hub for Afghanistan, and gives a total of $150 million a year in aid to Bishkek.

"It certainly doesn't make any sense for Russia or any other country in the region to try to undermine the international effort to bring stability to central Asia," Whitman said.

"They (Russia) have been very consistent in their public statements in the past about supporting the international effort to bring stability in Afghanistan as well as the region," he added.

Moscow has politically backed NATO's effort in Afghanistan and says it will be flexible on U.S. requests that supplies to Afghanistan be allowed to cross Russian territory.

But U.S. officials, who initially viewed Bakiyev's announcement to shut Manas as an effort to secure more money from Washington, said they had a list of alternate routes for the 15,000 U.S. personnel and 500 tons of cargo that pass through the base each month.

"We can absorb the closure," said a U.S. military official. "But the challenge is: How do we most efficiently do that?"

UZBEKISTAN

One potential option is Uzbekistan, where U.S. forces had an air base until 2005 when authorities evicted them after the West condemned the Uzbek government for opening fire on a political protest.

Moscow could hope to gain concessions from the West to halt the proposed expansion of NATO into Georgia and Ukraine and the cancellation of U.S. plans to build a missile defense shield in Poland and the Czech Republic.

"Russia doesn't have an interest in seeing Afghanistan implode," Welt said. "But we have to see what it's willing to offer on the other end. This is one step in a longer game."

U.S. officials seemed well aware of the potential for broader implications.

"It was not lost on us when Bakiyev said this on Russian television. I am not sure what the Russians are up to," said a State Department official.

The official said he doubted Russia could follow through with the money promised but declined to give further details.

Kyrgyz Prime Minister Igor Chudinov said Kyrgyzstan sought to shut down the base because it disagreed with U.S. methods in Afghanistan but would not interrupt the transit of nonmilitary cargo to that country.

"We are in talks with the U.S. side. We are terminating the air base agreement but we are not refusing to take part in Afghanistan's reconstruction," he told a news conference in the capital, Bishkek. (Additional reporting by Sue Pleming and Andrew Gray in Washington, Olga Dzyubenko in Bishkek and Dmitry Solovyov in Moscow; Editing by Peter Cooney)

AlertNet news is provided by