A Muslim cleric tied to the attempted bombing of a Detroit-bound airliner has become the first U.S. citizen added to a list of suspected terrorists the CIA is authorized to kill, a U.S. official said Tuesday.

Anwar al-Aulaqi, who resides in Yemen, was previously placed on a target list maintained by the U.S. military's Joint Special Operations Command and has survived at least one strike carried out by Yemeni forces with U.S. assistance against a gathering of suspected al-Qaeda operatives.

Because he is a U.S. citizen, adding Aulaqi to the CIA list required special approval from the White House, officials said. The move means that Aulaqi would be considered a legitimate target not only for a military strike carried out by U.S. and Yemeni forces, but also for lethal CIA operations.

"He's in everybody's sights," said the U.S. official, who spoke on the condition of anonymity because of the topic's sensitivity.

CIA spokesman Paul Gimigliano said: "This agency conducts its counterterrorism operations in strict accord with the law."

The decision to add Aulaqi to the CIA target list reflects the view among agency analysts that a man previously regarded mainly as a militant preacher has taken on an expanded role in al-Qaeda's Yemen-based offshoot.

"He's recently become an operational figure for al-Qaeda in the Arabian Peninsula," said a second U.S. official. "He's working actively to kill Americans, so it's both lawful and sensible to try to stop him." The official stressed that there are "careful procedures our government follows in these kinds of cases, but U.S. citizenship hardly gives you blanket protection overseas to plot the murder of your fellow citizens."

Aulaqi corresponded by e-mail with Maj. Nidal M. Hasan, the Army psychiatrist accused of killing 12 soldiers and one civilian at Fort Hood, Tex., last year. Aulaqi is not believed to have helped plan the attack, although he praised Hasan in an online posting for carrying it out.

Concern grew about the cleric's role after he was linked to the Nigerian accused of attempting to bomb a U.S. airliner on Christmas Day by detonating an explosive device he had smuggled in his underwear. Aulaqi acknowledged teaching and corresponding with the Nigerian but denied ordering the attack.

The CIA is known to have carried out at least one Predator strike in Yemen. A U.S. citizen, Kamal Derwish, was among six alleged al-Qaeda operatives killed in that 2002 operation but was not the target.