WASHINGTON -- Officials say U.S. aircraft could leave as early as Friday for the first mission to help evacuate refugees from the crisis in Libya.

Senior defense officials said Thursday that flights from Ramstein Air Base in Germany were being prepared following President Barack Obama's OK to use military planes to take home Egyptians who fled Libya and are stranded in Tunisia. The officials spoke on condition of anonymity because plans have not been officially announced.

Officials had no details on when the first flight from Tunisia to Egypt will be made after the aircraft arrive in North Africa, nor on how many refugees they would eventually take to Egypt. But they say it's likely the aircraft will be U.S. Air Force C-130 cargo planes, which can hold several dozen people.