The transfer was the latest and biggest push by the Biden administration in its final weeks to clear Guantanamo of the last remaining detainees there who were never charged with a

At its peak, about 680 people, most suspected of terrorism and being "illegal enemy combatants", were held at the American-run prison in Cuba. Now there are just 15 men left.

The secret mission left the smallest number of prisoners at Guantánamo Bay since the day the detention center opened in 2002.