The Pentagon’s new leader said Thursday that the Defense Department needs to make military life appealing to the next generation, adding that there is no “great galvanizing thing” like the 9/11 terrorist attacks to motivate them to serve.

Defense Secretary Ashton B. Carter’s comments came during a speech to more than 300 Pentagon employees two days after he was sworn in as the fourth defense secretary of President Obama’s tenure in office. He listed several major priorities of his before noting that differences exist between previous generations and current youth.

“These kids are different, and we need to think about how we make the conditions of service attractive to them,” Carter said. “What it takes to make them effective in an organization or on the battlefield. They behave differently, they think differently, they’ve grown up differently, and they’re used to a different kind of environment around them, and we have to make ourselves attractive to them.”

Carter was quick to add that “no one could wish something similar” to the attacks on Sept. 11, 2001, on the United States in the future. But he noted that it motivated many Americans to serve: “a terrific thing, but at a terrible price.”

The secretary did not provide specifics on what he believes might motivate military service in the future. But he cited three main priorities he highlighted in a message to Defense Department troops and employees on Tuesday. They include helping Obama make the right decisions for the nation, ensuring the strength and health of the present force, and building the future military.