Mullen isn't sure Flynn still has temperament to be national security adviser

Retired Lt. Gen. Mike Flynn had the temperament to serve as national security adviser while he was still in uniform, but comments made on the campaign trail are making a former Joint Chiefs chairman question his ability to take on that job in the Trump administration.

Retired Adm. Mike Mullen said Monday at the Aspen Institute that Flynn, who President-elect Trump named as his national security adviser last week, served as Mullen's intelligence officer in the Pentagon for a little over a year.

"He's a very creative guy and from what I saw took good care of people, treated people well, never had any inkling of not doing that when he was my intel officer," Mullen said.

But Mullen added that comments Flynn made during Trump's campaign are making him wonder if the retired officer is suited for the White House job, including Flynn encouraging chants of "lock her up" at the Republican National Convention.

"When I knew him, he clearly had the temperament. If it's the 'lock her up' temperament, that's not who I'd want to advise me from a national security perspective," Mullen said.