Former President Jimmy Carter jabbed President Donald Trump saying he made a “very serious mistake” in not initially lowering the White House flag to pay tribute to the late Sen. John McCain.

Carter, speaking on on Tuesday, said: “I think there was a very serious mistake that President Trump made. His friends and his opponents corrected him, I think, quite adequately.”

He also addressed Trump’s statement regarding McCain’s death.

“And now this most recent statement he's made, I would say is okay,” Carter said. “It’s still not as enthusiastic as it should be.

“I’m grateful that he finally made a statement that I think was at best adequate. Now that the flag is 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.”

For much of the day on Monday, the flag at the White House was flying at full-staff, despite other flags flying at half-staff to honor McCain.

The White House flag was lowered to half-staff at 3:30 p.m. Trump then about the longtime lawmaker.