Then-Democratic vice presidential candidate Kamala Harris (left) speaks during a debate Oct. 7, 2020, in Salt Lake City, and former President Donald Trump speaks during a debate June 27 in Atlanta. Trump said Friday that he's pulling out of a scheduled debate with his likely Democratic opponent, Vice President Harris, and instead has agreed to a date earlier in September on Fox News Channel.

Then-Democratic vice presidential candidate Kamala Harris (left) speaks during a debate Oct. 7, 2020, in Salt Lake City, and former President Donald Trump speaks during a debate June 27 in Atlanta. Trump said Friday that he's pulling out of a scheduled debate with his likely Democratic opponent, Vice President Harris, and instead has agreed to a date earlier in September on Fox News Channel. / AP

Vice President Kamala Harris responded to former President Donald Trump after he posted on social media about switching the date and format of the next televised presidential debate, saying she'd see him at the event "he already agreed to." Then Trump doubled down.

"I’ll see her on September 4th or, I won’t see her at all," he posted on his Truth Social platform, referring to a debate he says he agreed to with Fox News.

Trump, the GOP nominee for president, had originally agreed to debate President Biden on Sept. 10 on ABC News, but late Friday, Trump wrote that he had "agreed with Fox News" to debate Harris on Fox News instead, on Sept. 4.

Harris, the likely Democratic presidential nominee, responded on the social media platform X, saying it was "interesting how 'any time, any place' becomes 'one specific time, one specific safe space.' "

A statement from Harris' campaign said Trump was "running scared and trying to back out of the debate he already agreed to," and was now expecting Fox News to "bail him out."

The Harris statement continued that Trump was "playing games" and that the vice president would be happy to discuss further debates with him once Trump had participated on Sept. 10, as earlier agreed.

Trump said in his Truth Social posts that there were two reasons for his decision to switch from the originally scheduled ABC News debate: first, Biden's withdrawal from the race, and second, what he described as ongoing "litigation" against ABC and its chief political anchor, George Stephanopoulos, that he described as a "conflict of interest."

The Fox News-hosted debate that Trump referred to would be held, he wrote, in front of a full arena audience in Pennsylvania.

Trump also said the earlier date of Sept. 4 was "convenient and appropriate" since it would be just days before the start of early voting in the Nov. 5 presidential election.

A spokesperson for Fox News did not respond to a request for comment before publication.