As per American presidential tradition, Donald Trump used Thursday's National Prayer Breakfast to take a jab at Celebrity Apprentice host Arnold Schwarzenegger, who replaced him as the face of NBC's reality show. (Trump remains an executive producer on the series.)

"We had tremendous success on The Apprentice, and when I ran for president, I had to leave the show. That's when I knew for sure I was doing it," Trump told attendees at the morning event, which is held each year in February. "And they hired a big, big movie star, Arnold Schwarzenegger, to take my place. And we know how that turned out. The ratings went right down the tubes. It's been a total disaster. And [Apprentice creator and producer Mark Burnett] will never, ever bet against Trump again. And I want to just pray for Arnold if we can, for those ratings, OK?"

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It didn't take long for Schwarzenegger to fire back, posting this video on Twitter:

A spokesman for the former California governor told ABC News: "Arnold is praying that President Trump can start improving his own approval ratings, which were the worst in history for an incoming President, by taking his job seriously and working inclusively."

This isn't the first time Trump has poked at Schwarzenegger, who endorsed John Kasich in the Republican presidential primary and refused to back Trump publicly in the general election, over Celebrity Apprentice ratings. In January, before he was inaugurated as president, Trump had this to say:

Schwarzenegger has also recently criticized Trump's policy banning travelers from certain majority Muslim countries from entering the United States.