A look at who is still held at the detention center at the US base at Guantanamo Bay, Cuba

GUANTANAMO BAY NAVAL BASE, Cuba – President Barack Obama has appointed a new envoy to lead a renewed effort to close the detention center at the U.S. base at Guantanamo Bay, Cuba. Here's a look at where things stand:

— CURRENT POPULATION: The U.S. holds 166 men at the prison, down from a peak of about 680 in June 2003.

— GETTING OUT OF GUANTANAMO: Nearly 90 prisoners have been approved for either release or transfer, which in some cases will mean continued detention in their homeland or a third country. The new envoy appointed by Obama will be working with Congress and other countries to move them out of the U.S. base in Cuba.

— WAR CRIMES PROSECUTIONS: The total is unclear. Seven prisoners have been convicted so far by military commission, or a special tribunal for wartime offenses. Six more inmates currently face trial by commission, including Khalid Sheikh Mohammed, the self-proclaimed mastermind of the Sept. 11, 2001, terrorist attacks, and Abd al-Rahim al-Nashiri, who faces charges that include terrorism and murder for allegedly orchestrating the al-Qaida attack on the USS Cole in Yemen in 2000.

Charges are pending against two more. The chief prosecutor, Army Brig. Gen. Mark Martins, says the military may charge about seven more prisoners, but the number may increase if the U.S. develops additional evidence or witness testimony through plea bargains or other means.

— INDEFINITE DETENTION: The rest are detained "subject to the law of war," which means there is not enough evidence to charge them with a crime but they can be held as long as hostilities persist between the U.S. and al-Qaida and the Taliban, a length of time that remains uncertain.