President Barack Obama has sent a personal message to his Kyrgyzstan counterpart, officials said Thursday, as Washington tries to keep U.S. forces from being evicted from an important air base in the Central Asian nation.

In his letter, Obama thanked President Kurmanbek Bakiyev for Kyrgyzstan's support of U.S.-led military operations in nearby Afghanistan, the Kyrgyz president's office said in a statement.

The statement also quoted Obama as saying a delegation of senior U.S. officials will soon visit the poor former Soviet republic.

A U.S. Embassy spokesman in the Kyrgyz capital, Bishkek, couldn't be immediately reached for comment.

U.S. forces have had access to the Manas air base outside Bishkek since 2001. The base — a transit point for 15,000 troops and 500 tons of cargo each month to and from Afghanistan — became even more important to the Afghan war effort after neighboring Uzbekistan evicted U.S. troops from a base there.

But in February, Bakiyev stunned Washington by announcing the U.S. base would be closed, citing what he said was inadequate financial compensation and other concerns.

Russia, which has long been wary of the U.S. presence in Central Asia, was widely believed to be behind the decision. The announcement of the closure came shortly after Moscow, which also has an air base in Kyrgyzstan, pledged more than $2 billion in aid, loans and investment.

Kyrgyzstan has given U.S. forces until Aug. 18 to vacate Manas. But in recent weeks, speculation has grown that Kyrgyz officials might be reconsidering the decision.

Earlier this week, Afghan leader Hamid Karzai appealed to Kyrgyzstan to let coalition forces continue using Manas. Karzai is expected to meet Bakiyev for talks on the base during a summit in Russia later this month.

A Bakiyev spokesman, Almas Turdumamatov, talked down prospects of a new deal.

"The issue of the base has been resolved. The (lease) agreement was revoked. There are no negotiations about a new agreement," Turdumamatov said.

However, a prominent Kyrgyz political analyst said Thursday that a new agreement on the base has been reached already.

"At the moment, they are discussing terms for a new deal to rent Manas airport that is worth $350 million per year," Alexander Knyazev told The Associated Press. He refused to reveal his source for the information.

The United States currently pays $17.4 million annual rent for Manas, but contributes $150 million overall every year to the local economy through service contracts and aid packages, according to U.S. officials.

U.S. Defense Secretary Robert Gates has previously said that the United States would be willing to pay more, within reason.