"The change we've made today meets each of those standards and will make our nation stronger."
Unlike the US administration under Bush, who greatly sought to expand presidential powers during his term, the new detention policy does not rely on the president's powers as military commander in chief to hold terrorism suspects at Guantanamo.
Instead, the justice department said: "It draws on the international laws of war to inform the statutory authority conferred by Congress.
"It provides that individuals who supported al-Qaeda or the Taliban are detainable only if the support was substantial.
"And it does not employ the phrase "enemy combatant"."
The justice department said it had told the court that the Obama administration was reviewing its entire detention policy as part of its plan to close the prison at the US naval base in Cuba, and further refinements of the policies were possible.