The State Department said Thursday that the eviction of U.S. forces from the Manas air base in Kyrgyzstan will not adversely affect American and NATO military operations in Afghanistan. The Kyrgyz parliament has voted to end U.S. access to the base, although officials in Washington say the action is not final.

Officials here say they do not consider an eviction of U.S. forces from the Manas air base a foregone conclusion, despite the parliamentary vote. But they say that if Kyrgyz President Kurmanbek Bakiyev signs the legislation and formally ends the base agreement, the United States is ready to comply and find alternate arrangements.

U.S. forces have had access to the base for five years and it has become a major hub for U.S. military flights and refueling missions connected to the Afghan conflict, especially since the Uzbek government ended a similar basing arrangement with the United States in 2005.

At a news briefing, State Department Deputy Spokesman Gordon Duguid said dialogue with Kyrgyz authorities on the future of the base continues despite the parliamentary vote.

He said the United States will comply with an eviction order if that is the Kyrgyz government's final decision. But Duguid said that despite news reports to the contrary, it will not affect the U.S. war effort in Afghanistan.

"Not one whit. We will be able to continue our operations in Afghanistan fully and completely. The Pentagon is renowned for its ability to move troops, equipment and other materiel to all parts of the world," he said.

Duguid said the signing of base closure notice by the Kyrgyz government would start a 180-day period at the end of which U.S. forces would have to be gone. He said the Pentagon has contingency plans for a closure, and that it is examining options for replacing operations at Manas, although he declined to elaborate.

A senior State Department official who spoke to reporters here said the United States still has an offer on the table for increased compensation for Kyrgyzstan which has not been formally rejected by authorities in the capital Bishkek.

The official said a further and larger U.S. offer was a possibility, but that there is no indication the Kyrgyz side is open to further negotiations.

The Kyrgyz president announced this month that he would close the base after accepting more than $2 billion in Russian aid. U.S. officials have said that while they are willing to increase compensation for access to the base, it would not come close to the Russian aid pledge.

U.S. Defense Secretary Robert Gates, in Poland on Thursday, expressed irritation over Russia's role in the matter. He said Moscow is trying to "have it both ways" with respect to Afghanistan - on the one hand, expressing a readiness to cooperate with the United States while, on the other hand, "working against us" in terms of an air base clearly important to the war effort.