President Obama has not authorized drone missile strikes in Syria, however, and none are under consideration.

The Counterterrorism Center, which runs the CIA’s covert drone killing program in Pakistan and Yemen, recently shifted several targeting officers to improve intelligence collection on militants in Syria who could pose a terrorist threat, the officials said.

The targeting officers have formed a unit with colleagues who were tracking Al Qaeda operatives and fighters in Iraq. U.S. officials believe that some of these operatives have moved to Syria and joined Islamic militias battling to overthrow President Bashar Assad.

The CIA effort, which involves assembling detailed dossiers on key militants, gives the White House both lethal and nonlethal options if it concludes that Syria’s 2-year-old civil war — which has caused 70,000 deaths, according to United Nations estimates — is creating a haven for terrorists. The intelligence files also could be used to help opposition figures with moderate views prevail over extremists.