WASHINGTON — The United States is building a secret CIA air base in the Persian Gulf region to target terrorists in Yemen, preparing for the possibility that an anti-American faction may take over the country and ban U.S. forces from hunting a lethal al-Qaida faction there, The Associated Press has learned.

The anti-al-Qaida effort in Yemen is being run by the Joint Special Operations Command, the top U.S. military counterterrorism outfit, and the CIA provides intelligence support. JSOC forces have been allowed by the Yemeni government to conduct limited strikes there since 2009 and have recently allowed expanded strikes by U.S. armed drones and even warplanes against al-Qaida targets who are taking advantage of civil unrest to grab power and territory in the gulf country.

The new CIA base provides a backstop if al-Qaida or other anti-American rebel forces gain control, one senior U.S. official explained. The White House has already increased the number of CIA officers in Yemen in anticipation of that possibility. And it has stepped up the schedule to construct the base, from a two-year timetable to eight months.

The Associated Press has withheld the exact site at the request of U.S. officials. They spoke on condition of anonymity because portions of the military and CIA missions in Yemen are classified.

Drones like Reapers and Predators are unmanned aircraft that can be flown from remote locations and hover over a target before firing a missile. Yemeni officials have indicated their preference toward drones versus allowing U.S. counterterror strike teams on Yemeni soil, saying they are less apt to incense the local population.

The planned CIA base suggests a long-term U.S. commitment to fighting al-Qaida in the region, along the lines of the model used in Pakistan, where CIA drones hunt militants with tacit, though not public, Pakistani government approval. The base’s construction also indicates a possible shift in the internal debate in the administration over whether U.S. special operations forces should continue to lead the fight in Yemen, U.S. officials said.

While that policy debate plays out in Washington, U.S. special operations forces based just outside Yemen are taking aim almost daily at a greater array of targets that have been flushed into view by the unrest. U.S. forces have stepped up their targeting as well because of the besieged Yemeni government’s new willingness to allow U.S. forces to use all tools available – from armed drones to warplanes – against al-Qaida as a way to stay in power, the U.S. officials said.