Vice Adm. Adm. William H. McRaven, the top military official involved in the raid that killed Osama bin Laden, told a Senate committee plans for detaining the suspects are developed ad hoc, then approved by the White House, The Washington Post reported.
"That is always a difficult issue for us," McRaven said. "No two cases seem to be alike."
While questioned by senators, McRaven said suspects captured in clandestine operations by Navy SEALs or the Army's Delta Force are often taken to a U.S. Navy ship until trial in an American court or transfer to the custody of an allied country. And he said the U.S. military often releases prisoners because neither option is feasible.
"If we can't do either one of those, then we will release that individual," McRaven said in response to a question from Sen. Lindsey Graham, R-S.C. "I mean, that becomes the unenviable option, but it is an option."
He did not cite cases of prisoners having been freed.
McRaven and Lt. Gen. John R. Allen, Obama's nominee for commander of U.S. and NATO forces in Afghanistan, said the military recommended not transferring any terrorism suspects captured in countries, including Somalia, Yemen and Pakistan, to U.S. detention centers in Afghanistan because of political resistance in that country.
The Obama administration has pledged to shut down the prison at Guantanamo Bay, Cuba, which still holds 170 detainees captured after the Sept. 11, 2001, terrorist attacks.