WASHINGTON -- U.S. President Donald Trump says movie star Arnold Schwarzenegger "tried hard" to make "Celebrity Apprentice" a success, but has failed.

In an early morning Twitter post Friday, the president kept alive a theme he brought up a day earlier during his first appearance at the National Prayer Breakfast.

Trump, who once hosted the NBC reality TV show, took a pot shot there at Schwarzenegger, the current host and former California governor, over a ratings nosedive for the show.

On Friday, Trump said in his tweet, "Yes, Arnold Schwarzenegger did a really bad job as Governor of California and even worse on the Apprentice ... but at least he tried hard!"

Schwarzenegger responded quickly to Thursday's remarks in a video on his verified Twitter account, suggesting that he and Trump switch jobs.