James Mattis, a three-star general who served one tour of duty in Afghanistan and two in Iraq, made the remarks to a military audience in San Diego.
"You go into Afghanistan, you got guys who slap women around for five years because they didn't wear a veil," Mattis said. "You know, guys like that ain't got no manhood left anyway. So it's a hell of a lot of fun to shoot them."
Gen. Michael W. Hagee, commandant of the Marines, said Thursday he had spoken to Mattis about the statement.
"I have counseled him concerning his remarks, and he agrees he should have chosen his words more carefully," he told the New York Times.
Hagee went on to defend Mattis' record and character, calling him "one of this country's bravest and most experienced military leaders."