After Fox News scheduled to have South Bend, Indiana, Mayor Pete Buttigieg on Sunday night, President Donald Trump criticized the network, saying it was “wasting airtime.”

Buttigieg is among two dozen people competing for the Democratic Party’s 2020 nomination to challenge Trump.

Chris Wallace, the Fox News anchor, has previously praised the mayor for having “interesting, refreshing ideas.”

SLIDESHOW: TOP DEMOCRATS RUNNING FOR PRESIDENT IN 2020

The Democratic National Committee announced in March that it would not allow any presidential primary debates in this cycle to be hosted by Fox News, fearing the deep ties between the conservative network and Trump’s White House.

Fox News Senior Vice President and Managing Editor Bill Sammon responded by citing that Wallace along with fellow anchors Martha MacCallum and Brat Baier are “the best debate team in the business and they offer candidates an important opportunity to make their case to the largest TV news audience in America, which includes many persuadable voters.”