President Barack Obama on Wednesday ordered the Justice Department to share with Congress a classified memo that explains the legal rationale that justifies the targeted killing of Americans suspected of being members of al Qaida.

The decision came after years of refusing to make the memo available and two days after a Justice Department “white paper” that described the memo’s contents was made public. The memo provides the legal framework for U.S. drone attacks that have killed at least three American citizens and as many as 3,500 others.

Obama’s counter terrorism adviser, John Brennan, Obama’s nominee to head the CIA, is expected to face tough questioning over the program Thursday from the Senate Intelligence Committee considering his nomination.

“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,” the White House said in a statement emailed to reporters.

A further explanation provided by the White House said Obama made the decision in an effort to include Congress in discussion of the country’s counterterrorism policies. The explanation called the decision “an extraordinary action.”