In a reversal, President Barack Obama will hand lawmakers classified documents outlining the legal justification for drone strikes which kill US citizens abroad who are conspiring with al Qaeda.
An administration official disclosed the move on Wednesday on the eve of a Senate hearing on Obama's nomination of his top White House anti-terror advisor John Brennan to lead the Central Intelligence Agency in his second term.
Some senators had warned Brennan's confirmation could be in doubt if the administration did not share more information on the legal and constitutional grounding for the US government killing its own citizens.
The disclosure also comes after NBC News published an unclassified Justice Department white paper covering similar ground, reigniting the debate about the killing of estranged Americans who switched sides in the "War on Terror."
"Today, as part of the president's ongoing commitment to consult with Congress on national security matters, the president directed the Department of Justice to provide the congressional intelligence committees access to classified Office of Legal Counsel advice related to the subject of the Department of Justice White Paper," an administration official said.
Obama aides insist killing al Qaeda suspects, some of them US citizens, in places like Pakistan or Yemen, complies with US law and the Constitution, even when no intelligence links the targets to specific attack plots.
"We conduct those strikes because they are necessary to mitigate ongoing actual threats, to stop plots, to prevent future attacks and, again, save American lives," said White House spokesman Jay Carney said Tuesday.
"These strikes are legal, they are ethical, and they are wise."
Among the most controversial of the attacks were the September 2011 killings in Yemen of Anwar al-Awlaki and Samir Khan, which stoked concern because the pair were both US citizens who had never been charged with a crime.