President Obama will officially nominate former Deputy Attorney General James Comey to be the next director of the FBI at a ceremony Friday afternoon at the White House, according to an administration official.

The announcement will make formal the selection of the No. 2 official in former President George W. Bush's Justice Department. Comey had been seen as Obama’s top choice to replace outgoing Director Robert Mueller.

"In Jim Comey, the men and women of the FBI will have the leadership of one of our nation’s most skilled and respected national security and law enforcement professionals," said a White House official. "In more than two decades as a prosecutor and national security professional, Jim has demonstrated unwavering toughness, integrity and principle in defending both our security and our values."

Comey served briefly as acting attorney general during the Bush administration, during which he notably refused to sign a presidential order certifying domestic surveillance operations run by the National Security Agency.

White House chief counsel Alberto Gonzales and Chief of Staff Andrew Card attempted to bypass his decision by secretly visiting then-Attorney General John Ashcroft in the hospital, prompting Comey and FBI Director Mueller to threaten to resign.

Bush subsequently intervened, promising changes to the surveillance program to satisfy the objections raised by the Justice Department.

"Throughout his life, Jim has shown a deep commitment to the values that define us as Americans," the White House official said. "He has worked tirelessly to strengthen our nation’s legal framework."

The current director, Mueller, has served as the department's chief since 2001. Two years ago the Senate approved legislation allowing Obama to extend his term.

During his tenure, Mueller directed much of the agency’s attention on counterterrorism, a focus of Comey as well.

Mueller is leaving as the agency faces a number of questions, from his admission earlier this week that the FBI has used drones to spy domestically to whether more could have been done to identify and prevent the alleged Boston bombers.

Comey is also likely to face questions about his views on the secret NSA surveillance programs disclosed earlier this month by Edward Snowden.

The Senate must confirm the appointment, and there is some worry that it will be difficult to shepherd Comey through the process by the beginning of September, at which point Mueller is legally obligated to leave his post.

A graduate of the University of Chicago law school, Comey quickly moved up through the Justice Department's ranks. He also served as a member of the Defense Legal Policy Board, a group tasked with advising the Secretary of Defense on major legal and policy issues.

"In that capacity, he has helped develop improvements to the military justice system’s performance with respect to crimes committed in Iraq and Afghanistan," the White House said.

Since leaving the federal government, Comey taught law at Columbia University and worked as general counsel for the money management firm Bridgewater Associates. Prior to that, he was an executive at Lockheed Martin.