The last three Uighurs who had languished in the US prison at Guantanamo Bay for over a decade without charge have been freed and sent to Slovakia, officials said Tuesday.

As the world was ushering in 2014, the men were swapping the austere, remote military facility in southeastern Cuba for a refugee camp in their new homeland.

"They are already in Slovakia. They will now stay at a camp for migrants, learn Slovak and get ready for a new life," interior ministry spokesman Ivan Netik told AFP.

Yusef Abbas, 38, Saidullah Khalik, 36, and Hajiakbar Abdul Ghuper, 39, were the last of a group of 22 ethnic Chinese Muslims captured in a mountain camp in Afghanistan in 2001.

"The inmates we received were never suspected, let alone convicted of crimes," Netik said, adding the authorities were looking for jobs for them.

The releases, part of stepped up efforts by the administration of US President Barack Obama to fulfill a long-held pledge to close the jail, were announced earlier Tuesday by the Pentagon.

"This transfer and resettlement constitutes a significant milestone in our effort to close the detention facility at Guantanamo Bay," Pentagon press secretary John Kirby said, thanking Slovakia for taking in the three men.

They had all been cleared since 2008 for release from the detention facility -- opened in the wake of the September 11, 2001, attacks on the United States -- but Washington refused to return them to China where they faced persecution, and had struggled to find a third country to take them in amid protests from Beijing.

Asked about pressure from China, Ian Moss, spokesman for the State Department's office of the special envoy for the closure of Guantanamo, acknowledged there had been difficulties.

"The United States has worked diligently to generate resettlement opportunities for these three individuals and has engaged a number of different governments to seek their resettlement," he told AFP.

"It is a challenging task to resettle anyone from Guantanamo, but the Uighurs presented a particularly complex set of circumstances."

The three men were also the last of a group of five who had fought a long battle to be relocated in the United States, which failed when the Supreme Court refused in April 2012 to take up their appeal.

All 22 Uighurs have been now resettled in six countries including Albania, Bermuda, El Salvador, Palau, and Switzerland.

"The United States is grateful to the government of Slovakia for this humanitarian gesture and its willingness to support US efforts to close the Guantanamo Bay detention facility," Kirby added in his statement.

State Department special envoy Cliff Sloan added Washington had cooperated closely over the transfers with Slovakia, which took in three other ex-detainees in 2010.

"We have worked together on humanitarian migration issues for many years, and this important humanitarian action reflects Slovakia's sustained assistance, which, on the issue of Guantanamo, began in 2009," Sloan said in a statement.

The jail had become a symbol of some of the worst excesses of the "war on terror" under the previous administration of president George W. Bush.

But Obama's initial efforts to shut it down stalled, stymied by Republicans' refusal to allow detainees to be transferred to US soil either for trial or release.

In recent months, efforts have accelerated as lawmakers work on easing restrictions to sending individuals back home or to third nations prepared to accept them.

A total of 155 prisoners now remain in Guantanamo, with 76 having been cleared for release, of which 55 hail from Yemen.

Six others were released this month, sent back to Algeria, Saudi Arabia and Sudan.

The Uighurs -- members of a largely Muslim people who have long accused China of discrimination -- had been staying in a special part of the prison with a library and recreational space.

They hail from China's western Xinjiang region, which in 2009 witnessed some of the country's deadliest ethnic violence in years.

The Guantanamo releases were announced a day after Chinese authorities said they shot dead eight "attackers" armed with knives and explosives during a "terrorist attack" on a police station.

An exiled Uighur group called Tuesday for an independent investigation into the incident.