WASHINGTON (AP) — Small teams of special operations forces arrived at American embassies throughout North Africa in the months before militants launched the fiery attack that killed the U.S. ambassador in Libya. The soldiers' mission: Set up a network that could quickly strike a terrorist target or rescue a hostage.

The White House signed off a year ago on the plan to build the new military counterterror task force in the region, and the advance teams have been there for six months, according to three U.S. counterterror officials and a former intelligence official. All spoke only on condition of anonymity because they were not authorized to discuss the strategy publicly.

The effort indicates that the administration has been worried for some time about a growing threat posed by al-Qaida and its offshoots in North Africa. But officials say the military organization was too new to respond to the attack in Benghazi, where the administration now believes armed al-Qaida-linked militants surrounded the lightly guarded U.S. compound, set it on fire and killed Ambassador Chris Stevens and three other Americans.