The department filed a notice to judges presiding over the cases at the US District Court in Washington to advise them that by the end of next week the Justice Department would file official motions to dismiss the cases.
The notice comes a week after George Bush, the US president, signed new legislation banning cruel and inhumane treatment of prisoners. The anti-torture law also curbs the ability of prisoners being held at the US Naval Base in Cuba to challenge their detention in federal court.
The legislation requiring humane treatment of detainees in US custody was originally opposed by the White House. But Bush backed off his original veto threats after Congress voted overwhelmingly to support the amendment, pushed by Senator John McCain, an Arizona Republican who was a prisoner of war in Vietnam.
In a concession to the White House, the bill limits prisoners from going to lower-level civilian courts for relief from confinement. They can only go to an appeals court once they have gone through a military court process.
The United States has faced criticism at home and abroad for treatment of prisoners at Guantanamo and for holding prisoners indefinitely. Only nine of about 500 prisoners being held at the base have been charged, and the United States has been holding prisoners there since January 2002.
Hundreds of prisoners have filed lawsuits in civilian courts to protest their confinement or to protest conditions of confinement.