'Sad moment' when Kelly showed he’ll support Trump 'no matter what': Mullen A former joint chiefs chair expressed concern about generals setting policy.

 -- A former chairman of the Joint Chiefs of Staff said he is concerned about retired or active generals serving in high-level roles in the White House at a time of sharp partisan divisions in the nation.

Ret. Adm. Michael Mullen told ABC News "This Week" co-anchor Martha Raddatz that White House Chief of Staff John Kelly, a retired Marine Corps general; National Security Adviser H.R. McMaster, an active-service Army general; and Secretary of Defense Jim Mattis, a retired Marine Corps general, are all "great Americans" who want to do the best for their country.

But Mullen pointed to concerns such as when Kelly stepped in to defend President Donald Trump after the president’s phone call to the widow of Sgt. La David Johnson, who was among four soldiers killed in an ambush in Niger.

Kelly made a surprise appearance at a White House press briefing in October to defend the president against criticism over the phone call. He also attacked Rep. Frederica Wilson, D-Fla., for listening in on and sharing the details of Trump’s call to Gold Star widow Myeshia Johnson.

“It stuns me that a member of Congress would have listened in on that conversation. Absolutely stuns me,” Kelly said. “And I thought at least that was sacred.”

Mullen said Sunday that Kelly's comments were "really a sad moment for me."

The episode indicated, Mullen said, that Kelly "clearly is very supportive of the president no matter what.”

"That doesn't mean generals and admirals can't serve," in the White House, the retired admiral said. "They certainly have in the past. But it's particularly difficult right now because of the politics of the town. And there's nothing that seemingly is not able to be politicized in the current environment."