Defense officials have said that of around 170 detainees at Guantanamo, about 80 are expected to face trial by military commission.
On Monday, the White House reiterated its commitment to eventually close Guantanamo — which is on a U.S. Navy base on an isolated corner of Cuba — and said Monday's actions were in pursuit of that goal.
Critics of the military commission system, which was established specifically to deal with the detainees at Guantanamo, contend that suspects are not given some of the most basic protections afforded people prosecuted in American courts. That situation, critics say, serves as a recruitment tool for terrorists.
Obama's administration has enacted some changes to the military commission system while aiming to close down Guantanamo.
More than two dozen detainees have been charged there, and so far six detainees have been convicted and sentenced. They include Ali Hamza al-Bahlul, Osama bin Laden's media specialist, who told jurors he had volunteered to be the 20th Sept. 11 hijacker. He is serving a life sentence at Guantanamo.
Meanwhile, the first Guantanamo detainee tried in civilian court — in New York — was convicted in November on just one of more than 280 charges that he took part in the al-Qaida bombings of two U.S. embassies in Africa. That case ignited strident opposition to any further such trials.
The Justice Department had planned to have Mohammed's trial in New York, but Obama bowed to political resistance and blocked it.
Under Obama's direction Monday, Defense Secretary Robert Gates issued an order rescinding his January 2009 ban against bringing new cases against the terror suspects at the Cuba prison. Gates said the U.S. must maintain the option of prosecuting alleged terrorists in U.S. federal courts, but in his order Monday he also said the review of each detainee's status had been completed and the commission process had been reformed to address legal challenges.