AIR FORCE ACADEMY, Colo. — Defense Secretary Jim Mattis says the 984 new lieutenants who are graduating from the U.S. Air Force Academy should be prepared to face war.

The Colorado Springs Gazette reports Mattis told the 2018 graduates on Wednesday they must be ready to fight and win. He spoke at the graduation ceremony on the campus outside Colorado Springs.

Mattis told them they must maintain U.S. military superiority in the air. He urged them to make the Air Force better.

As the ceremony ended, the newly commissioned officers threw their white hats into the sky as the Air Force Thunderbirds roared overhead, a longstanding tradition.

This year marks the 60th class to graduate from the academy.

More than 400 are headed to pilot training, and 69 will be trained to operate drones.