Ten Yemeni former inmates from the US detention centre in Guantanamo Bay arrived in Oman on Thursday, Muscat's foreign ministry said, as Washington struggles to close the notorious prison.

The transfer is the largest to a single country at any one time under the administration of US President Barack Obama, and brings the facility's population down to 93.

About 780 inmates have been held there since it opened in January 2002.

"Just last night, after a deliberate and careful review, we completed the transfer of 10 Yemenis -- roughly 10 percent of the total remaining Gitmo population -- to the government of Oman," US Defence Secretary Ashton Carter said in Florida.

"Like every transfer that came before it, the decision to transfer these detainees happened only after a thorough review by me and other senior security officials of the government."

The 10 men are: Fahed Abdullah Ahmad Ghazi, Samir Naji al-Hasan Muqbil, Adham Mohamed Ali Awad, Mukhtar Yahya Naji al-Warafi, Abu Bakr Ibn Muhammad al-Ahdal, Muhammad Salih Husayn al-Shaykh, Muhammad Said Salim Bin Salman, Said Muhammad Salih Hatim, Umar Said Salim al-Dini, and Fahmi Abdallah Ahmad Ubadi al-Tulaqi.

Oman received the men "in response to a request by the US administration for help to resolve the issue of detainees at Guantanamo Bay," the foreign ministry said in a statement carried by state news agency ONA.

The statement did not give further details, but typically Guantanamo inmates are released on condition they undergo a rehabilitation or reintegration programme to make sure they do not threaten US security interests.

The United States has been working to repatriate low-risk inmates from the Guantanamo facility, located at a US naval base on the southeastern tip of Cuba.

Another former Guantanamo inmate was repatriated this week to Saudi Arabia, where he was to join the kingdom's programme to rehabilitate militants.

On January 9, the last Kuwaiti prisoner at the detention centre returned home to a family reception after 14 years of detention.

And in November, the Pentagon said that the United States had transferred five detainees from Guantanamo Bay to the United Arab Emirates.

The Republican-controlled Congress has thwarted Obama's repeated efforts to close Guantanamo.

He came to office in 2009 vowing to shutter the facility, which opened under his predecessor George W. Bush to hold suspects after the September 11, 2001 attacks and became known for harsh interrogation techniques that some have said were tantamount to torture.

Inmates were called "enemy combatants" and denied standard US legal rights, meaning many were held for years without charge or trial.

In his final State of the Union address on Tuesday, Obama again urged Congress to help him close the detention facility.

"It's expensive, it's unnecessary and it only serves as a recruitment brochure for our enemies," he said.