COLORADO SPRINGS, Colo. (AP) — President Joe Biden on Thursday thanked U.S. Air Force Academy graduates for choosing “service over self” but said they now have the “great privilege” of leading in a world that will only get more confusing in the years to come.

“Graduates, you made a noble choice to lead a life of service,” Biden told more than 900 cadets in remarks on the sun-splashed field at Falcon Stadium in Colorado. “Now you also shoulder a great privilege and a mighty responsibility. Leadership, yeah leadership.”

“In the years ahead, your airmen and guardians are going to look to you for guidance and inspiration because the world is going to get more confusing," he added. “They'll put their trust in you. You, in turn, must strive to always be worthy of their confidence.”

Biden said they will need the qualities of resilience, creativity, endurance and commitment that they learned during their four years of training at the academy — learning that was interrupted by the COVID-19 pandemic — to deal with a range of global challenges. He said that ranged from Russia's aggression in Ukraine and America's rivalry with China “to a whole hell of a lot in between.”

He also cited the threat of climate change and the growing use of artificial intelligence.

“Never forget the sacred oath you swear, and the mission you serve is something far, far greater than any person or president," Biden said. "It's our Constitution, it's our country and it's our enduring American values.”

More than 900 academy graduates will become second lieutenants in either the Air Force or Space Force. Biden said it was the most diverse in the academy's history and he called on the graduates to “root out the scourge of sexual assault and harassment in the military.”

The ceremony was to be capped by an aerial salute to the graduates by the world-renowned U.S. Air Force Air Demonstration Squadron, the Thunderbirds, flying over Falcon Stadium. Biden met with some of the pilots on Wednesday after he arrived at Peterson Space Force Base.