The US in January 2002 began using Guantanamo Bay Naval Base in eastern Cuba to hold people suspected of links to al Qaeda or the Taliban. A total of 759 detainees have been held at the base, the Pentagon says.
About 275 detainees have been released or transferred from Guantanamo. The US now holds about 480 detainees.
The Pentagon says 136 detainees have been approved for release or transfer, but their departure depends on several factors, including the willingness or ability of their home countries to take them and for the US to be assured the detainees will be treated humanely.
The US has filed charges against 10 detainees. In April, the chief military prosecutor said the US plans to file charges against about two dozen more detainees and will seek the death penalty in an unspecified number of cases.
All military tribunals are in the pretrial stage.
The Supreme Court is expected to rule in June on the legality of the tribunal process.