There are currently 164 detainees at the Guantanamo Bay prison, many of whom have not been formally charged, but are being held under the Authorization for the Use of Military Force, The Washington Post reported.
The AUMF was passed in the days following the Sept. 11, 2001 terror attacks and allows military force to be used against those who "planned, authorized, committed or aided" in the attacks.
Obama said in a speech in May that he would like to "refine, and ultimately repeal" the law and replace it with one that allows action against new al-Qaeda related groups in the Middle East and Africa.
A senior administration official said repealing the law would allow allow Guantanamo inmates to refile habeas corpus petitions that were previously denied by the U.S. government, the newspaper reported.
Some Congress members who signed the AUMF into law said they are concerned about the open-ended nature of the law.
"I never imagined that the AUMF would still be in effect today," said former Rep. Jane Harman, D-Calif. "Over time, some would assert, and I agree, that it has taken on a life of its own, and the executive branch has used it in ways that no one who voted for it envisioned."
However, there have not yet been any moves by the administration to implement Obama's plan for repealing the AUMF.