Updated

A one-time top CIA official and a former ambassador to Syria and Iraq are calling on the U.S. to ramp up the air campaign against Islamic State militants in Syria and set up a safe zone to protect citizens from Syrian President Bashar Assad's bombing raids.

Ambassador Ryan Crocker told the House Armed Services Committee on Wednesday that the air war needs to be increased to "actually degrade" IS. Crocker said a safe zone would serve a humanitarian goal and signal Sunnis in the region that the U.S. is not against them — only Sunni extremists.

John McLaughlin, former acting director of the CIA, said the U.S. needs to increase the intensity of the air campaign, send more U.S. special operators, set up a safe zone and arm local forces.