Read Donald Trump's tweets about Megyn Kelly and Fox's response

Rematch: Donald Trump vs. Megyn Kelly
Rematch: Donald Trump vs. Megyn Kelly

Donald Trump has kept up his Twitter attacks on Fox News anchor Megyn Kelly this week.

Trump called her "crazy," "average" and "sick." He also said she was "highly overrated" and called for a boycott of her show because there's "always a hit on" him.

Trump has had an issue with Kelly since she moderated a Republican presidential debate in August. He accused her of being unfairly harsh on him.

On Saturday morning, Trump said "crazy" Kelly's "ratings would totally tank" if she wasn't constantly covering him. He also said her show was "terrible" and that she was "average in so many ways."

On Friday, Trump called for a boycott of her show.

Earlier this week, Trump said her show was "unwatchable" and that she was "highly overrated & crazy." He also urged her to "[f]ocus on others" and accused her of "always complaining about Trump."

Related: Megyn Kelly says Bill O'Reilly didn't have her back with Donald Trump

Fox News is standing by its anchor, calling the attacks on her "sexist verbal assaults."

"Donald Trump's vitriolic attacks against Megyn Kelly and his extreme, sick obsession with her is beneath the dignity of a presidential candidate who wants to occupy the highest office in the land," the network said in its statement.

"Megyn is an exemplary journalist and one of the leading anchors in America — we're extremely proud of her phenomenal work and continue to fully support her throughout every day of Trump's endless barrage of crude and sexist verbal assaults," the statement continued. "As the mother of three young children, with a successful law career and the second highest rated show in cable news, it's especially deplorable for her to be repeatedly abused just for doing her job."

Newsletter

CNNMoney Sponsors