Former New Jersey Gov. Chris Christie said on Sunday that fellow 2024 GOP presidential candidate Donald Trump is a “petulant child” when it comes to those, particularly his former allies, who disagree with him.

The indicted former president recently went on his Truth Social platform to rip his former staff and allies who have criticized him for knowingly keeping classified documents at Mar-a-Lago after leaving the White House, and trying to prevent the National Archives from obtaining those documents. Trump has pleaded not guilty to all charges ― some of which fall under the Espionage Act ― handed by a federal grand jury.

Among those he went after were former White House chief of staff John Kelly and former Attorney General Bill Barr, both of whom have recently criticized Trump for mishandling top secret government documents. In one post, the ex-president said that Kelly is weak and has a “very small brain.” In another post, Trump called Barr a “gutless pig,” “lazy” and “totally ineffective.”

Speaking on CNN’s “State of the Union,” Christie pointed out that the very people Trump is berating are the same officials he gave high praise to when he hired them during his presidency.

“Now look, either Donald Trump ― if you believe what he said when [the officials] left ― that means he didn’t pick the very best people and doesn’t know how to pick personnel. If you believe, about them, what he said at the beginning, the great stuff, then this guy is the worst manager in the history of the American presidency,” the presidential candidate said.

“Either way, Republicans should listen to what he says. He’s a petulant child when someone disagrees with him. And whether it’s Bill Barr or John Kelly or [former Defense Secretary] General [James] Mattis, whether it is [former White House official] Mick Mulvaney or whether it’s … [Chairman of the Joint Chiefs of Staff] General [Mark] Milley ― if you disagree with Donald Trump, the petulant child comes out and he calls you names like the ones you just mentioned and the ones I mentioned.”

Christie was one of over a dozen Republicans running for the presidential nomination in 2016, and after dropping out became the first major endorser of Trump. The New Jersey Republican supported Trump through all of his controversies while in the White House, even after the former president infected him with COVID-19 at a 2020 debate prep session. As a result, Christie spent a week in intensive care at the hospital.

The former New Jersey governor withdrew his support for Trump after the ex-president lied about voter fraud in the 2020 election, and incited a mob of followers to attack the Capitol on Jan. 6, 2021. Christie, who is now running for the 2024 Republican presidential nomination, was one of the first of Trump’s GOP rivals to go after him for the Justice Department’s special counsel indicting him with 37 felony counts related to the classified documents.

The Republican National Committee announced this year that all GOP candidates must sign a pledge to support the eventual nominee in order to participate in the primary debates, regardless of whether the nominee is a convicted felon. When asked if he would support Trump should he be the nominee, Christie called the idea of a pledge “useless.”

“I’m going to take the pledge just as seriously as Donald Trump took it in 2016. As you will remember, [former RNC chair] Reince Priebus had to go up to Trump Tower to get him to sign [the pledge], to ask him to do so. He did,” the New Jersey Republican said.

“And then we went to a subsequent debate, and we were all asked if we would reaffirm our support of whoever the nominee was going to be by raising our hand. There were 10 of us on the stage ― nine of us raised our hands. The one who didn’t was Donald Trump. And so I will take the pledge in 2024 just as seriously as Donald Trump took the pledge in 2016.”