Add Fox News anchor Bill O'Reilly to the stable of media personalities Donald Trump has deemed worthy of the cold shoulder.

On his show Thursday, O'Reilly interviewed the Republican front-runner's nearest rival, Ted Cruz, and said that Trump is denying interviews because he's unhappy with the anchor.

"I know you defend him a lot, Bill, that's your prerogative," Cruz said to O'Reilly, who is generally sympathetic to Trump and admittedly friends with the billionaire.

"I defend him on points that I think are valid but I go after him and that's why he's not on the program," O'Reilly said. "Because he's mad at me."

The previous night, O'Reilly said that he has worked for several days on getting Trump to appear on his show but without success. He said that there is "angst" within the Trump campaign over the guests O'Reilly has had on his show and who have been critical of him.

Trump is often combative with journalists in media personalities, most famously with O'Reilly's colleague Megyn Kelly.