Ammon News - WASHINGTON (Reuters) - Yemeni President Abd-Rabbu Mansour Hadi talked to U.S. senators on Wednesday as he to tries to persuade Washington to repatriate dozens of Yemeni detainees from the Guantanamo Bay prison.

Expectations that the Obama administration is moving closer to its long-held goal of closing the facility were raised last week when the White House announced it was sending two detainees back to Algeria in the first repatriations for nearly a year.

Yemen is key to any closure of Guantanamo, for 56 of the 86 detainees who have been cleared for transfer or release are from the impoverished country on the Arabian Peninsula.

But al Qaeda's regional wing is active in Yemen, worrying U.S. officials who fear that released prisoners would eventually join up with Islamist militants.

President Barack Obama promised in May to end a ban on transferring Yemenis back home but no announcement on a decision to release detainees is expected when he meets Hadi at the White House on Thursday, administration officials said.

"I have no reason to believe any releases are imminent," said David Remes, a lawyer for some of the Yemenis detained at Guantanamo. "Everybody says the right thing, and then nothing happens."

The Republican-controlled House of Representatives recently voted twice to block the transfer of detainees to Yemen. Hadi met on Wednesday with members of the Senate foreign relations committee. There is less resistance to shuttering the prison in the Senate, where Obama's fellow Democrats hold a slim majority.

A handful of Senate Republicans, including Arizona's influential Senator John McCain, also want it shut.

The United States halted repatriations to Yemen in 2010 after a man trained by militants there attempted to bomb a U.S.-bound plane in 2009 with a bomb concealed in his underwear.

Transfers to Yemen are more likely to resume if Washington decides its new government has taken adequate measures against al Qaeda and made the country stable.

"You can't expect them to be able to do this overnight," a senior administration official said. "There was some success last year where they kind of drove out al Qaeda from their stronghold, but then the threat has evolved somewhat.

"Al Qaeda has shifted to a different kind of campaign in Yemen, where it is no longer about controlling territory in the south, but it's about hit and run, assassination, guerilla-type tactics," the official said. "So it's about how to adapt to and enhance the Yemenis' ability to address the evolving threat."