WASHINGTON: President Barack Obama nominated James Comey to be the new FBI director Friday, tapping a Bush-era Justice Department official to lead the agency as it grapples with privacy debates over a host of recently exposed investigative tactics.

Obama praised Comey for demonstrating unyielding integrity in the face of uncertainty. Flanked by Comey and his outgoing FBI director, Robert Mueller, in a sunny White House Rose Garden announcement, Obama said Comey recognises that in times of crisis, America is judged not only by how many plots are disrupted, but also by its commitment to civil liberties and the ideals espoused in the Constitution. ''Jim understands, deeply in his core, the anguish of victims of crime _ what they go through,'' Obama said. ''He's made it his life's work to spare others that pain.''

''He's a rarity in Washington sometimes: He doesn't care about politics,'' Obama added.

Comey is perhaps best-known for a remarkable 2004 standoff at the hospital bedside of Attorney General John Ashcroft over a no-warrant wiretapping program. Comey rushed to the room of his bedridden boss to physically stop White House officials from trying to get an ailing Ashcroft to reauthorise the program.

If confirmed by the Senate, Comey would serve a 10-year term and replace Mueller, who has held the job since the week before the terrorist attacks on Sept. 11, 2001. Obama praised Mueller effusively and said he could declare without equivocation that countless Americans are alive today because of Mueller's efforts. Mueller is set to resign on Sept. 4 after overseeing the bureau's transformation into one the country's chief weapons against terrorism.

Comey was a federal prosecutor who served for several years as the US attorney for the Southern District of New York before coming to Washington after the Sept. 11 attacks as deputy attorney general. In recent years, he's been an executive at defence company Lockheed Martin, general counsel to a hedge fund, board member at HSBC Holdings and lecturer on national security law at Columbia Law School.

The White House may hope that Comey's Republican background and strong credentials will help him through Senate confirmation at a time when some of Obama's nominees have been facing tough battles. Republicans have said they see no major obstacles to his confirmation, although he is certain to face tough questions about his hedge fund work and his ties to Wall Street as well as how he would handle current, high-profile FBI investigations.

The FBI is responsible for both intelligence and law enforcement with more than 36,000 employees. It has faced questions in recent weeks over media leak probes involving The Associated Press and Fox News; the Boston Marathon bombings; the attack at Benghazi, Libya, that killed four Americans; and two vast government surveillance programs into phone records and online communications.

The leaker of those National Security Agency programs, former NSA contractor Edward Snowden, also is the subject of an ongoing criminal investigation. And just this week, Mueller revealed the FBI uses drones for surveillance of stationary subjects and said the privacy implications of such operations are worthy of debate.

''This work of striking a balance between our security but also making sure we're maintaining fidelity to those values that we cherish is a constant mission,'' Obama said.