WASHINGTON — Vowing to look hard at problems inside the Air Force’s nuclear missile corps, Defense Secretary Chuck Hagel said Friday it’s clear “something is wrong” and he is determined to restore public confidence in the nuclear force.

Hagel told reporters that he is sure the problems will get fixed and that the nation’s arsenal of nuclear weapons will remain safe and secure. He said he will convene a high-level meeting soon to probe the problems.

At a Pentagon news conference, Hagel said the issues are complex and derive from a post-Cold War mindset that has reduced the focus on the nuclear weapons mission and led people to “just take for granted” that it will function correctly.

“This is cultural,” he said, noting that the U.S. military has been intensely involved in fighting wars in Iraq and Afghanistan for more than a decade, conflicts with little direct relevance to the mission of nuclear warriors.

“Over the years I do think we have taken some focus off of the responsibilities of these very dedicated, very bright young officers” who operate intercontinental ballistic missiles, or ICBMs, stationed in five U.S. states, he said.

Hagel was commenting on the Air Force’s dual investigations of drug use and exam cheating within its nuclear missile force, as well as a series of disclosures last year by The Associated Press about security lapses, leadership failures and other problems among those who operate and protect the Minuteman 3 missile force.

On Thursday, he announced that he also will assemble a small group of outside nuclear experts to study personnel problems within the nuclear force and to recommend remedies. Hagel has not yet said who will serve on that panel.

Later Friday, Hagel raised the nuclear issue during welcoming remarks for Air Force Secretary Deborah Lee James at her ceremonial swearing-in at the Pentagon. He said he is “deeply concerned” about the “overall health, professionalism and discipline of our (nuclear) forces.”

“Recent allegations regarding our ICBM force raise legitimate questions about this department’s stewardship of one of our most sensitive and important missions,” Hagel said, adding that he is determined to fix whatever is wrong.

“Restoring confidence in the nuclear mission will be a top priority,” he said.