Jimmy Carter is busy building Habitat houses in Indiana this week, but he put down his hammer long enough on Tuesday to wade into the John McCain-Donald Trump flag flap.

>> Read more trending news

“I think that was a very serious mistake that President Trump made and his friends and his opponents corrected him, I think, quite adequately,” Carter, 93, said on “Andrea Mitchell Reports” on MSNBC. “And now that this most recent statement he’s made, I’d say, is OK. It’s still not as enthusiastic as it should be.”

McCain died on Saturday at age 81, more than a year after being diagnosed with a malignant brain tumor. After initially lowering the White House flags to half-staff that day, Trump had them raised again to full staff on Sunday. And they stayed that way until late Monday afternoon when the president -- clearly battered by the public outcry and criticism from veterans groups and even some members of his own staff -- ordered them lowered again and issued a statement offering his condolences to McCain's family.

On Tuesday, Mitchell wondered what Carter made of it all.

"As a former president can you explain or justify an American president for hours and hours refusing to lower the American flag and not even mentioning the death of an American hero, a former prisoner of war?" she asked Carter, a graduate of the U.S. Naval Academy at Annapolis like McCain.

Rosalynn and Jimmy Carter at work on Monday, Aug. 27, 2018, in Mishawaka, Indiana as part of Habitat’s Jimmy & Rosalynn Carter Work Project.
icon to expand image

A little later, she pressed Carter for some more possible insight into the current Oval Office occupant:

"There's a pettiness in the President's responses to these people that he has rivalries with. In the moment of death of an American hero can't you overcome those political differences?" she asked.

"Well, most people can and I think that President Trump has a problem with that on occasion," Carter responded. "But I'm grateful that he finally made a statement that I think his – I'd say at the best adequate, now that the flag is going to be lowered during an appropriate period on behalf of John McCain to remember him, I think is very good. So, I'm glad to see that it was done, although it was tardy and mistaken at first."

Two memorial services were planned for McCain. The first was held Wednesday at the Arizona state Capitol. The second is scheduled for Saturday at the Washington National Cathedral.

John McCain Fast Facts