"I have absolute confidence that Mark will ensure that our incredible military is fully prepared to deter conflict and to defeat any foe," Trump said at the ceremony. "No enemy can match the awesome might of the American Army, Navy, Air Force, Coast Guard, and the United States Marines."
Trump said that the West Point graduate with 21 years of military service has incredible support. He noted the military budget has been boosted by "billions of dollars" since he came into office.
He also noted the 9/11 terrorist attacks of the Pentagon.
"Today, we stand not far from where terrorists attacked the Pentagon on 9/11, claiming 184 precious lives," Trump said. "We will never forget the immortal sacrifice of those American patriots. We vow to do whatever it takes to protect our homeland, to safeguard our people from the threat of radical Islamic terrorism, and to preserve American freedom."
Esper thanked Trump for his confidence in him.
"Mr. president, thank you sir, for your confidence in me and this opportunity," Esper said. "It is an honor of a lifetime to be appointed secretary of defense and to lead the greatest military in history, and I am especially humbled that you would be here to celebrate this occasion."
Esper also mentioned the historic significance of the Pentagon building and thanked the military.
"This historic building is not only the headquarters of our armed forces, it is a prominent symbol of America's military power and of our willingness to defend our people and our interests around the world," he said. "I want to thank the great patriots, military and civilian alike, who come to work here and focus on one thing, supporting the more than 2 million soldiers, sailors, airmen and Marines who sacrifice and serve in defense of our great nation. They all represent America's best, and I'm proud to serve with them and alongside them."
The Senate voted 90-8 to confirm him Tuesday.