U.S. President Barack Obama prepares to sign the executive order to close the prison at Guantanamo Bay within a year, on Jan. 22. (Charles Dharapak/Associated Press)

The administration of U.S. President Barack Obama said Friday that it is abandoning what was one of former president George W. Bush's key phrases in the war on terrorism: enemy combatant.

The Justice Department said in legal filings that it will no longer use the term to justify holding prisoners at Guantanamo Bay.

However, Obama still asserts the military's authority to hold the detainees at Guantanamo Bay. The Justice Department simply says that authority comes from Congress and the international laws of war, not from the president's own wartime power, as Bush had argued.

The Obama administration's position on use of the phrase enemy combatants came in response to a deadline by U.S. District Judge John Bates, who is overseeing lawsuits of detainees challenging their detention. Bates asked the administration to give its definition of whom the United States may hold as an "enemy combatant."

The filing, while notifying the court the term will be dropped, reaffirms Bush's stance that the U.S. has authority to hold detainees, even if they were not captured on the battlefield in the course of hostilities. In their lawsuits, detainees have argued that only those who directly participated in hostilities should be held.

"The argument should be rejected," the Justice Department said in its filing. "Law-of-war principles do not limit the United States' detention authority to this limited category of individuals. A contrary conclusion would improperly reward an enemy that violates the laws of war by operating as a loose network and camouflaging its forces as civilians."

Retired army Lt.-Col. Stephen Abraham, a former Guantanamo official who has become critical of the legal process, said it's a change in nothing but semantics.

"There's absolutely no change in the definition," Abraham said in a telephone interview. "To say this is a kinder, more benevolent sense of justice, is absolutely false."

Among the estimated 245 detainees still being held in Guantanamo is Canadian Omar Khadr, who is accused of killing an American soldier during a battle in Afghanistan in July 2002. Khadr was 15 at the time.

While Obama's administration is saying the U.S. has a right to hold the detainees, the president has ordered the Guantanamo prison closed within a year.