Former president Jimmy Carter apparently isn’t a fan of John Bolton.

While speaking to multiple media outlets on Monday, Carter tore into President Trump for his decision to hire the ex-US ambassador as his new national security adviser — calling it “a disaster for our country.”

“Maybe one of the worst mistakes that President Trump has made since he’s been in office is his employment of John Bolton, who has been advocating a war with North Korea for a long time and even an attack on Iran, and who has been one of the leading figures on orchestrating the decision to invade Iraq,” Carter said during an interview with USA Today.

“I am concerned as a matter of fact about his deliberate moves to get into the key positions of government just people who agree with him,” the 93-year-old added. “Access to different opinions before you make a final decision is very valuable, and in the last few days I think President Trump’s choice of close advisers, powerful advisers, have gone to unanimity rather than diversity.”

Carter took his assessment a step further while speaking to CBS “This Morning” in an interview set to air Tuesday.

“I think John Bolton has been the worst mistake he’s made,” the 39th president said, calling Trump’s move “very ill-advised.”

“I have been concerned at some of the things he’s decided.”

While Carter did not appear to give specifics as to why Bolton was a bad choice for national security adviser, the former UN ambassador has been known to criticize him in the past for his handling of the Iranian Revolution in the late ’70s.

Trump selected Bolton last week after giving H.R. McMaster the boot, according to reports.

One of Carter’s biggest fears about Bolton is that he will mishandle the negotiations over North Korea’s nuclear weapons program. He told USA Today that his “first advice” to Trump, if they were ever to sit down and discuss the situation, would be to fire Bolton immediately.

“What the North Koreans have wanted for a long time is just assurance confirmed by the Six Powers Agreement — with China and Russia and Japan and South Korea and so forth — that the United States will not attack North Korea as long as North Korea stays at peace with its neighbors,” Carter said.

The former president’s interviews with USA Today and CBS will be published in full on Tuesday, as part of the release of his new book, titled “Faith: A Journey for All.”