LISBON — In what could draw the United States into another conflict in North Africa, the Obama administration has pledged to help the French who are fighting Islamist militants in Mali, and that assistance could include air and other logistical support, Defense Secretary Leon E. Panetta said on Monday.

The United States was already sharing intelligence with the French when their warplanes on Sunday struck camps, depots and other militant positions deep inside extensive Islamist-held territory in northern Mali. Defense officials said no decisions had been made on whether the United States would also offer help with midflight refueling planes and air transport, but they said those options were under review.

Defense officials would not rule out the possibility that American military transport planes might land in Mali, where the United States has been conducting an ambitious counterterrorism program for years. American spy planes and surveillance drones are in the meantime trying to get a sense of the chaos on the ground. The defense officials would not discuss whether the United States has armed drone aircraft over Mali.