The order, ending a block Gates imposed the day of U.S. President Barack Obama's inauguration, is "an acknowledgment the prison in Cuba remains open for business after Congress imposed steep new impediments to closing the facility," The New York Times reported Thursday.
Removing the ban would clear the way for military tribunal officials to bring new charges against detainees for the first time by the Obama administration, the Times said.
Charges would then probably be filed within weeks against one or more detainees designated by the Justice Department for prosecution before a military commission, the newspaper said.
A military tribunal is a military court designed to try members of enemy forces during wartime, operating outside the scope of conventional criminal and civil proceedings.
Detainees likely to face new charges include Abd al-Rahim al-Nashiri, accused of planning the Oct. 12, 2000, USS Cole bombing in Yemen; Ahmed al-Darbi, accused of plotting an attack on oil tankers in the Strait of Hormuz; and a detainee known only as Obaydullah, accused of concealing bombs, the Times said.
More than 30 new cases may be prosecuted, the newspaper said.
The Obama administration also plans to create a "parole board" system to periodically review cases of some 50 detainees held without trial, the Times said.
A military commissions system spokeswoman declined comment.