Detainees in orange jumpsuits sit in a holding area under the watchful eyes of military police during in-processing to the temporary detention facility at Camp X-Ray of Naval Base Guantanamo Bay in this January 11, 2002 file photograph. A cache of classified U.S. military documents provides intelligence assessments on nearly all of the 779 people who been detained at the Guantanamo Bay prison in Cuba. The secret documents, made available to The New York Times and several other news organizations, reveal that most of the 172 remaining prisoners have been rated as a "high risk" of posing a threat to the United States and its allies if released without adequate rehabilitation and supervision, the newspaper said in its report late on April 24, 2011. REUTERS/Stringer/Files (CUBA - Tags: CRIME LAW POLITICS) 

A sample cell is displayed within Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba, June 3, 2017. REUTERS/Carlos Barria SEARCH "GUANTANAMO COMBO" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A Koran is shown hanging in a cell in Camp Delta at the Guantanamo Bay Naval Station in Guantanamo Bay, Cuba September 4, 2007. The U.S. military is building a mobile courtroom complex on an unused runway at the Guantanamo Bay naval base and plans to be ready by March to conduct as many as three terrorism trials at a time. Picture taken September 4, 2007. REUTERS/Joe Skipper (CUBA) 

An unidentified prisoner reads a newspaper in a communal cellblock at Camp VI, a prison used to house detainees at Guantanamo Bay U.S. Naval Base, March 5, 2013. The facility is operated by the Joint Task Force Guantanamo and holds prisoners who have been captured in the war in Afghanistan and elsewhere since the September 11, 2001 attacks. Picture taken March 5, 2013. REUTERS/Bob Strong (CUBA - Tags: POLITICS MILITARY CRIME LAW TPX IMAGES OF THE DAY) 

Military Police at camp X-Ray on the Naval Base at Guantanamo Bay bring a detainee, who arrived at the camp injured, to an interrogation room for questioning February 2, 2002. There are one hundred and fifty eight detainees presently in Guantanamo Bay. 

The outside of the "Camp Five" detention facility is seen at U.S. Naval Station Guantanamo Bay December 10, 2008, in this image reviewed by the U.S. military. Camp Five, modelled after a U.S. maximum security facility, houses the most uncooperative detainees, along with those of high intelligence value. REUTERS/Mandel Ngan/Pool (CUBA) 

A detainee is escorted by military police at Camp 4 of the maximum security prison Camp Delta at Guantanamo Naval Base in Guantanamo Bay, Cuba, August 26, 2004. This week the U.S. Military held preliminary hearings for four detainee's charged with conspiracy to commit war crimes. REUTERS/Mark Wilson/Pool mw/jf/HK 

Trays of halal meat for detainee meals are stored in a refrigeration unit at the U.S. Naval Base at Guantanamo Bay March 7, 2013. The Joint Task Force Guantanamo is responsible for housing and feeding prisoners who have been captured in the war in Afghanistan and elsewhere since the September 11, 2001 attacks. Detainees are given a daily choice of regular, soft, vegetarian, vegetarian with fish, bland and high fiber meals. Picture taken March 7, 2013. REUTERS/Bob Strong (CUBA - Tags: POLITICS MILITARY CRIME LAW) 

U.S. Army Military Police escort a detainee to his cell during in-processing to the temporary detention facility at Camp X-Ray in Naval Base Guantanamo Bay in this file photograph taken January 11, 2002 and released January 18, 2002. Al Qaeda leader Osama bin Laden was killed in a firefight with U.S. forces in Pakistan on May 1, 2011, ending a nearly 10-year worldwide hunt for the mastermind of the Sept. 11 attacks. "Justice has been done," U.S. President Barack Obama declared in a hastily called, late-night White House speech announcing the death of the elusive head of the militant Islamic group behind a series of deadly bombings across the world. REUTERS/Stringer/Files (CUBA) BEST QUALITY AVAILABLE 

A soldier shows an arrow that points to Mecca inside of sample cell within Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson 

A meal, identical to ones prepared for detainees at the Guantanamo Bay Naval Station is shown in Guantanamo Bay, Cuba September 5, 2007. The Items on the tray and in the open container are served to detainees. Picture taken September 5, 2007. REUTERS/Joe Skipper (CUBA) 

Improvised weapons are displayed on a wall by Joint Task Force Guantanamo at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson TPX IMAGES OF THE DAY SEARCH "GUANTANAMO BAY" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES. ?? 

Items given to detainees at Camp Delta are shown in a cell at the Guantanamo Bay Naval Station in Guantanamo Bay, Cuba September 4, 2007. Picture taken September 4, 2007. REUTERS/Joe Skipper (CUBA) 

Detainees participate in an early morning prayer session at Camp IV at the detention facility in Guantanamo Bay U.S. Naval Base August 5, 2009. The detention facility, which opened after the deadly Sept. 11, 2001 attacks on the United States, became a symbol of detainee abuse and detention without charge under the previous administration of George W. Bush. U.S. President Barack Obama has vowed to close Guantanamo Bay, which currently holds some 225 detainees, and has also ordered a stop to harsh interrogation methods. Picture taken August 5, 2009. REUTERS/Deborah Gembara (CUBA POLITICS CRIME LAW RELIGION CONFLICT IMAGES OF THE DAY) 

A pain chart with writing in Arabic hangs on the wall inside of Joint Task Force Guantanamo's detainee hospital at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson TPX IMAGES OF THE DAY

Detainees sit together inside the Camp 6 detention facility at Guantanamo Bay U.S. Naval Base in Cuba, May 31, 2009. The United States has made a new request for Australia to accept a group of detainees from Guantanamo Bay for resettlement, a government spokeswoman said on Saturday. The request is the first by President Barack Obama's administration, which plans to close down the detention camp in Cuba within the next year. REUTERS/Brennan Linsley/Pool (CUBA MILITARY POLITICS CRIME LAW) 

No photography signs are posted on the fence surrounding Camp Delta at the U.S. Naval Base at Guantanamo Bay, March 6, 2013. The facility is operated by the Joint Task Force Guantanamo and holds prisoners who have been captured in the war in Afghanistan and elsewhere since the September 11, 2001 attacks. Picture taken March 6, 2013. REUTERS/Bob Strong (CUBA - Tags: POLITICS MILITARY CRIME LAW) 

Detainees speak in the recreation area in Camp Six, the highest security prison at the Guantanamo Bay Naval Station in Guantanamo Bay, Cuba September 4, 2007. The U.S. military is building a mobile courtroom complex on an unused runway at the Guantanamo Bay naval base and plans to be ready by March to conduct as many as three terrorism trials at a time. Picture taken September 4, 2007. REUTERS/Joe Skipper (CUBA) 

Military Police at camp X-Ray on the Naval Base at Guantanamo Bay, Cuba, bring a detainee to an interrogation room, February 6, 2002. There are one hundred and fifty eight detainees in Guantanamo Bay. REUTERS/Marc Serota 

A 'restraint chair' and other equipment of the type used in force-feeding detainees is seen during a media tour of the Guantanamo Bay military prison at Guantanamo Bay U.S. Naval Base, in this picture taken April 19, 2016. Participation in what was once a widespread hunger strike has dwindled and fewer than five inmates are still being force-fed, the chief medical officer told reporters. REUTERS/Matt Spetalnick 

In this photo, reviewed by a U.S. Department of Defense official, a Guantanamo detainee's feet are shackled to the floor as he attends a "Life Skills" class inside the Camp 6 high-security detention facility at Guantanamo Bay U.S. Naval Base April 27, 2010. REUTERS/Michelle Shephard/Pool (CUBA - Tags: MILITARY POLITICS IMAGES OF THE DAY) 

A soldier puts on rubber gloves before interacting with detainees within a cell block that is a part of Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson SEARCH "GUANTANAMO BAY" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES. ?? 

Guards stand next to a TV as journalists visit the movie room at the "Camp Four" detention facility at U.S. Naval Station Guantanamo Bay December 10, 2008 in this image reviewed by the U.S. military. Camp Four houses the most "compliant" detainees where they live in a more open, community oriented manner. REUTERS/Mandel Ngan/Pool (CUBA) 

A recreation area in the maximum security Camp Six is shown at the Guantanamo Bay Naval Station in Guantanamo Bay, Cuba September 4, 2007. Picture taken September 4, 2007. REUTERS/Joe Skipper (CUBA) 

A ping pong table for detainees sits in the middlle of a court yard at Camp Delta at Guantanamo Naval Base August 23, 2004 in Guantanamo, Cuba. Four suspected al Qaeda fighters will be formally charged with war crimes this week as the U.S. military opens the first legal hearings for foreign prisoners captured during the war in Afghanistan and held at a remote U.S. Navy base in Cuba. [Beginning on Tuesday, the prisoners from Australia, Sudan and Yemen will appear separately, unshackled and in civilian clothing before a panel of five U.S. officers who will read the charges against them at the arraignments, officials at the Guantanamo base said on Sunday.] 

A detainee watches television while being held in Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson 

A soldier shows entertainment options that are available to detainees in Joint Task Force Guantanamo's library at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson SEARCH "GUANTANAMO BAY" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES. ?? 

A detainee stands at a table while being held in Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson SEARCH "GUANTANAMO BAY" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES. ?? 

Items not allowed to be brought within Joint Task Force Guantanamo's Camp VI sit in a cabinet at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. REUTERS/Lucas Jackson SEARCH "GUANTANAMO BAY" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES. ?? 

The interior of an unoccupied cell showing standard issue clothing given to prisoners is seen at Camp VI, a prison used to house detainees at the U.S. Naval Base at Guantanamo Bay, March 5, 2013. The facility is operated by the Joint Task Force Guantanamo and holds prisoners who have been captured in the war in Afghanistan and elsewhere since the September 11, 2001 attacks. Picture taken March 5, 2013. REUTERS/Bob Strong (CUBA - Tags: POLITICS MILITARY CRIME LAW) 

A holding pen used to transfer prisoners and materials is seen in an an unoccupied communal cellblock at Camp VI, a prison used to house detainees at the U.S. Naval Base at Guantanamo Bay March 5, 2013. The facility is operated by the Joint Task Force Guantanamo and holds prisoners who have been captured in the war in Afghanistan and elsewhere since the September 11, 2001 attacks. Picture taken March 5, 2013. REUTERS/Bob Strong (CUBA - Tags: POLITICS MILITARY CRIME LAW) 

In this photo, reviewed by a U.S. Department of Defense official, a Guantanamo detainee runs inside an exercise area at the detention facility at Guantanamo Bay U.S. Naval Base April 27, 2010. REUTERS/Michelle Shephard/Pool (CUBA - Tags: MILITARY POLITICS) 

Leg restraints are seen under desks in the classroom of "Camp Four" during a media visit to U.S. Naval Station Guantanamo Bay December 10, 2008 in this image reviewed by the U.S. military. The recently started art class is popular with the detainees. Camp Four houses the most "compliant" detainees where they live in a more open, community-oriented manner. REUTERS/Mandel Ngan/Pool (CUBA) 

Books in Arabic are seen on shelves at the detainee library located inside Camp Delta at the U.S. Naval Base at Guantanamo Bay, March 7, 2013. The facility is operated by the Joint Task Force Guantanamo and holds prisoners who have been captured in the war in Afghanistan and elsewhere since the September 11, 2001 attacks. Picture taken March 7, 2013. REUTERS/Bob Strong (CUBA - Tags: POLITICS MILITARY CRIME LAW) 

A view of a cell at the medium security prison inside Camp IV at the detention facility in Guantanamo Bay U.S. Naval Base August 4, 2009. The detention facility, which was opened after the deadly Sept. 11, 2001 attacks on the United States, became a symbol of detainee abuse and detention without charge under the previous administration of George W. Bush. U.S. President Barack Obama has vowed to close Guantanamo Bay, which currently holds some 225 detainees, and has also ordered a stop to harsh interrogation methods. Picture taken August 4, 2009. REUTERS/Deborah Gembara (CUBA POLITICS CRIME LAW) 

In this photo reviewed by U.S. military officials, a detainee whose name, nationality, and facial identification are not permitted, holds onto a fence as a U.S. military guard walks past the grounds of the maximum security prison at Camp 5 in the Guantanamo Bay U.S. Naval Base June 26, 2006. REUTERS/Brennan Linsley/Pool (CUBA) 

An operating room is seen in Camp Delta at the U.S. Naval Base Guantanamo Bay, Cuba January 18, 2006. About 500 detainees captured as part of Operation Enduring Freedom during the war in Afghanistan are held in the prison's complexes. REUTERS/Joe Skipper 

A detainee holds prayer beads while standing in the courtyard at Camp 4 inside of the maximum security prison Camp Delta at Guantanamo Naval Base in Guantanamo Bay, Cuba, August 26, 2004. This week the U.S. Military held preliminary hearings for four detainee's charged with conspiracy to commit war crimes. REUTERS/Mark Wilson/Pool mw/jf/HK 

Sgt. First Class Todd Rundle, non-commissioned officer-in-charge of Camp 4 of Camp Delta explains living conditions for detainees in a less-secure facility at the U.S. Naval Base Guantanamo Bay, Cuba July 28, 2004. With cooperation with interrogators, detainees can be transferred to Camp 4, where they can enjoy more privileges than in other facilities, including having roommates, more exercise and reading lessons. REUTERS/Joe Skipper JLS 

U.S. Marines escort a new detainee into a joint interrogation facility at Camp X-Ray February 10, 2002 at the naval base at Guantanamo Bay, Cuba. There are now 220 detainees at the camp. REUTERS/Marc Serota 

Detainees talk together inside the open-air yard at the Camp 4 detention facility at Guantanamo Bay U.S. Naval Base in Cuba, May 31, 2009. REUTERS/Brennan Linsley/Pool (CUBA MILITARY CRIME LAW CONFLICT) 

A U.S. Army soldier stands guard from atop a tower at maximum security prison Camp Delta at Guantanamo Naval Base, August 25, 2004 in Guantanamo, Cuba. Australian al Qaeda suspect David Hicks sat stoically before a U.S. military tribunal that formally charged him with war crimes on Wednesday and showed no emotion as his lawyers questioned the panel's ability to try him fairly. Hicks, a 29-year-old convert to Islam, is among the first four suspected al Qaeda fighters held at the remote U.S. naval base to face criminal charges of plotting attacks against America and its allies. The four are appearing before a military tribunal this week for pretrial hearings. REUTERS/Mark Wilson/POOL mw/jf/HB 

A U.S. Army soldier closes the gate at maximum security prison Camp Delta at Guantanamo Naval Base August 25, 2004 in Guantanamo, Cuba. Australian al Qaeda suspect David Hicks sat stoically before a U.S. military tribunal that formally charged him with war crimes on Wednesday and showed no emotion as his lawyers questioned the panel's ability to try him fairly. Hicks, a 29-year-old convert to Islam, is among the first four suspected al Qaeda fighters held at the remote U.S. naval base to face criminal charges of plotting attacks against America and its allies. The four are appearing before a military tribunal this week for pretrial hearings. REUTERS/Mark Wilson/POOL mw/jf/HB 

A table is seen at a restaurant used by U.S. military personnel at the Guantanamo Bay U.S. Naval Base, Cuba, June 3, 2017. REUTERS/Carlos Barria SEARCH "GUANTANAMO COMBO" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

An unidentified member of the U.S. Army walks by an empty prison camp at the U.S. Naval Base in Guantanamo Bay, Cuba, June 4, 2017. REUTERS/Carlos Barria SEARCH "GUANTANAMO COMBO" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

An exit door where released detainees are turned over to the countries that have agreed to accept them is seen at the Guantanamo Bay U.S. Naval Base, Cuba, June 3, 2017. REUTERS/Carlos Barria SEARCH "GUANTANAMO COMBO" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.