Four U.S. Army Green Berets were killed and two wounded in the Oct. 4 attack by suspected Islamist State terrorists in the southwestern part of the country.
"A patrol that is an area where the enemy has not operated before was ambushed and hit hard," Mattis told reporters traveling with him to Tampa. "And within 30 minutes the French airplanes were overhead."
Mattis said the French aircraft were "fast movers with bombs on them ready to help." Additionally, helicopters also were used to support the commandos.