Political insiders perceive ABC News as an ally of the Democrat party, although Fox News has not generally been pro-Trump, especially since Paul Ryan, former speaker of the House, became a member of the Fox Corporation Board of Directors.

"Donald Trump is running scared and trying to back out of the debate he already agreed to and running straight to Fox News to bail him out. He needs to stop playing games and show up to the debate he already committed to on Sept 10," Harris campaign communications director Michael Tyler told Newsweek.

"The Vice President will be there one way or the other to take the opportunity to speak to a prime time national audience. We're happy to discuss further debates after the one both campaigns have already agreed to. Mr. Anytime, anywhere, anyplace should have no problem with that unless he's too scared to show up on the 10th," he added.

Late Friday, Trump said he agreed to debate Harris on Fox News on September 4. "The Debate was previously scheduled against Sleepy Joe Biden on ABC, but has been terminated in that Biden will no longer be a participant," he posted on Truth Social.

"The FoxNews Debate will be held in the Great Commonwealth of Pennsylvania, at a site in an area to be determined," he continued. "The Moderators of the Debate will be Bret Baier and Martha MacCallum, and the Rules will be similar to the Rules of my Debate with Sleepy Joe, who has been treated horribly by his Party – BUT WITH A FULL ARENA AUDIENCE!"

President Joe Biden and Trump previously agreed to debate on September 10, but after Biden dropped out of the race, Steven Cheung, Trump's campaign communications director, said on July 25 the event was scuttled.

"[It] would be inappropriate to schedule things with Harris because Democrats very well could still change their minds," he said at the time.