(UPI) -- President Obama bowed to congressional demands for secret legal memos on targeted killings of U.S. terrorism suspects overseas, an administration official said.

The reversal came as John Brennan, Obama's chief counter-terrorism adviser, was to face a confirmation hearing Thursday as Obama's next CIA director. The Senate Intelligence Committee hearing was to begin at 2:30 p.m. EST.

Brennan has been the administration's chief architect of so-called targeted killings and deadly drone strikes against al-Qaida militants, including U.S.-born Anwar al-Awlaki.

Senate Democrats and Republicans had threatened to delay Brennan's hearing and possibly reduce his chances for confirmation.

Obama ordered the Justice Department to hand over the lengthy "Legal Council advice" document to the intelligence panels of both chambers "as part of the president's ongoing commitment to consult with Congress on national security matters," the administration official said.

Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., said in a statement she was "pleased" with the decision.

"It is critical for the committee's oversight function to fully understand the legal basis for all intelligence and counterterrorism operations," her statement said.

The committee expected to receive the document Thursday morning, she said.

The 2010 Justice Department memo provided the administration's legal basis for a Sept. 30, 2011, CIA drone attack in Yemen that killed Awlaki.

Obama has described Awlaki, born in Las Cruces, N.M., as the "external operations" chief for al-Qaida in the Arabian Peninsula, regarded by the administration as al-Qaida's most powerful and influential anti-U.S. threat, responsible for several unsuccessful attacks on the United States.

The administration earlier described the document as an internal "work product" that does not have to be shared with Congress.

But lawmakers accused the administration of hypocritical secrecy in refusing to release the legal opinions on targeted killings -- opinions the administration refused to even officially acknowledge until late Wednesday.

The lawmakers said refusing to release the documents was similar to President George W. Bush's refusal to provide access to legal memos justifying the use of harsh interrogation methods against terrorism suspects.

Obama released those classified memos shortly after taking office in 2009.

Administration officials said Obama took the action out of a desire to involve Congress in the legal framework for targeting specific al-Qaida militants. Obama made a pledge to do that during an appearance on Comedy Central's "The Daily Show" last year, aides cited by The New York Times said.

Brennan said in written answers to the Senate panel, released Wednesday ahead his hearing, U.S. drone strikes against al-Qaida militants were legal.

"These strikes are conducted in full compliance with the law," wrote Brennan, whose official title is deputy national security adviser for homeland security and counter-terrorism.

"In fact, extraordinary care is taken to ensure they conform to the law of war principles," he wrote in response to a question about the legality, ethics and wisdom of targeted strikes against specific al-Qaida terrorists.

The law of war is a body of law and legal criteria used to determine whether entering into war is legally permissible and justifiable. It also deals with the limits to acceptable wartime conduct.

The United States applies "rigorous standards and a rigorous process of review" before engaging combat drones, Brennan wrote.

"We are working to refine, clarify and strengthen this process and our standards," he added.

His comments and the White House reversal came after a 16-page U.S. Justice Department "white paper," based on the previously secret "Legal Council advice" document, surfaced. The unclassified white paper spells out the administration's case for killing suspected terrorists, including Americans, accused of being al-Qaida operatives.

The paper, first reported Monday by NBC News, says Washington can lawfully kill suspected terrorists overseas, including U.S. citizens, if "an informed, high-level official" determines the person is a "senior, operational leader" of al-Qaida or one of its affiliates and poses "an imminent threat of violent attack against the United States," provided his capture was not feasible.

U.S. authorities do not need to conclude a specific attack will take place "in the immediate future" before ordering a drone strike, the memo says.

The memo can be found at tinyurl.com/justicedeptmemo.

Brennan's written answers to Senate Intelligence Committee questions can be found at tinyurl.com/prehearingquestions.

Concerning civilian casualties, Brennan wrote that "regrettably and despite our best efforts," civilians are sometimes killed in drone strikes.

"It is exceedingly rare, and much, much rarer than many allege," he wrote. "When it does happen, however, we not only take account of the human tragedy, but we also go back and review our actions and examine and modify our practices where appropriate, so that we are doing everything possible to prevent the loss of innocent life in the future."