DUBAI, United Arab Emirates — Oman said Monday it accepted 10 detainees from the US prison at Guantanamo Bay ahead of President Obama leaving office, part of his efforts to shrink the facility he promised to close.

Oman’s Foreign Ministry said in a statement that it had accepted the prisoners at Obama’s request. It did not name the prisoners.

‘‘In consideration of their humanitarian situation, 10 persons have been released from detention and arrived in the sultanate today for a temporary residence,’’ the statement said.

A US defense official, speaking on condition of anonymity as the transfer had yet to be publicly announced by the government, confirmed the prisoners had been sent to Oman. The official declined to elaborate.

The Omani Embassy in Washington said it had no other information about the transfer. The US Embassy in Muscat declined to comment.

The Oman decision reduces the detention center population to 45. Days ago, authorities said 19 of the remaining 55 prisoners at the US military base in Cuba were cleared for release and could be freed in the final days of Obama’s presidency.

The sultanate of Oman, on the eastern edge of the Arabian Peninsula, previously accepted 10 Guantanamo prisoners from Yemen in January 2016. Oman also took another six in June 2015. Neighboring Saudi Arabia took four prisoners earlier this month and the United Arab Emirates took 15 in the largest-single transfer during Obama’s administration in August.

Oman, ruled by Sultan Qaboos bin Said since 1970, has served as an interlocutor between the West and Iran. It also has negotiated a number of prisoner releases in recent years for Western countries.

Obama has been unable to fulfil promises to close the facility in part because of congressional opposition to transferring any of the detainees to US prisons. Congress ultimately banned the transfer of prisoners to US soil for any reason.

Donald Trump, who will be inaugurated Friday as America’s 45th president, said during his campaign that he not only wants to keep Guantanamo open but ‘‘load it up with some bad dudes.’’ That’s put pressure on the Obama administration to find places to send as many of the prisoners abroad as possible this week.

The United States began using its military base on southeast Cuba’s isolated, rocky coast to hold prisoners captured during the Afghanistan invasion, bringing the first planeload on Jan. 11, 2002. At its peak, 18 months later, the facility held nearly 680 detainees.

There were 242 prisoners when Obama took office in 2009, pledging to close what became a source of international criticism over the mistreatment of detainees and the notion of holding people indefinitely, most without charge.

The majority of Guantanamo prisoners released have been sent to Afghanistan, Saudi Arabia, and Pakistan.