"Ethics and character are absolute values that we cannot take for granted," Hagel said during a news conference Friday. "Competence and character are not mutually exclusive. They are woven together."
During the next few weeks, the Pentagon will be announcing actions the service units are taking to deal with the ethical problem and will coordinate actions on the issue, he said.
"This will be an absolute top priority," Hagel said.
Hagel has been coping with allegations of security lapses and poor morale in the U.S. nuclear force. The U.S. Air Force said Jan. 15 it has suspended security clearances for at least 34 nuclear missile launch officers suspected of cheating on a proficiency exam.
"I don't think there is one simple answer to the issue of ethics, values, a lapse in some of those areas that we do know about," Hagel said. "That's why we're taking a hard look at this."
He said the Pentagon needs to find out the breadth and depth of the problem as well.
"I think we need to find out, is there a deep, wide problem?" he said. "If there is, then what's the scope of that problem? How did this occur? Was it a constant focus of 12 years on two long land wars, taking our emphasis off some of these other areas? I don't know. We intend to find out."