The Obama administration transferred the last three Uighur Muslim detainees at Guantanamo Bay to Slovakia, the Pentagon announced on Tuesday.

The three men, Yusef Abbas, Saidullah Khalik and Hajiakbar Abdul Ghuper, were cleared by a federal judge for transfer in 2008 but have languished in the prison as the administration tried to find a country to accept them.

The U.S. government feared the trio would face harsh treatment if returned to their native China, so the administration negotiated a deal to resettle them in Slovakia, a location the detainees found agreeable.

The Pentagon hailed the transfer as a “significant milestone” in President Obama's five-year attempt to close the Guantanamo Bay facility.

This year Obama reaffirmed his commitment to close the prison and since August has transferred eight other prisoners including two Saudis and two Algerians who were repatriated to their countries earlier this month.

“The transfer and resettlement constitutes a significant milestone in our effort to close the detention facility at Guantanamo Bay,” said Rear Adm. John Kirby, the Pentagon's spokesman.

Another 155 detainees are left at Guantanamo, a majority of whom are Yemeni. While the transfer of the Uighurs is relatively uncontroversial, the prospect of repatriating the Yemeni detainees has sparked concern on Capitol Hill because the country is a hotbed for al Qaeda. A terrorist threat emanating from Yemen and Pakistan in August forced the State Department to close a record number of embassies around the world.

Kirby said the interagency Guantanamo Review Task Force conducted a “comprehensive review” of the Uighurs' cases, including security issues, and all six agencies on the task force unanimously agreed to designate them for transfer.

“The United States is grateful to the government of Slovakia for this humanitarian gesture and its willingness to support U.S. efforts to close the Guantanamo Bay detention facility,” he said. “The United States coordinated with the government of Slovakia to ensure the transfer took place in accordance with appropriate security and human treatment measures.”

Human rights groups applauded the transfer of the Uighurs and thanked Slovakia for agreeing to resettle the trio.

The Center for Constitutional Rights issued a statement saying the Uighur detainees had become pawns in a “geopolitical saga” involving an agreement by the United States to hold them as “terrorists” in exchange for China's agreement not to interfere with U.S. efforts to obtain a United Nations Security Council resolution that paved the way for the U.S. invasion of Iraq in March 2003.

“It is especially heartbreaking that when the Uighurs were turned over to U.S. forces following the invasion of Afghanistan, they thought they have been saved,” CCR said. “They viewed America as the only superpower capable of standing up to China, and thought that they would be treated fairly and humanely. Sadly, they came to symbolize the tragedy of Guantanamo.”