It won't be long before the metaphorical gloves come off and rhetorical punches are thrown at Tuesday's first presidential debate between President Trump and Joe Biden, "Special Report" host and Fox News chief political anchor Bret Baier predicted Tuesday.

"Both campaigns know that the first 30 minutes of this debate is really where the most eyeballs will be watching, so expect fireworks early, if they are coming," Baier told "Your World" host Neil Cavuto.

Earlier Tuesday, White House press secretary Kayleigh McEnany told "America's Newsroom"  that Trump looks forward to "jousting back and forth" with Biden on the debate stage in Cleveland.

Trump has repeatedly attacked Biden's mental acuity and fitness for office, highlighting the former vice president's frequent gaffes in campaign ads and speeches. However, Baier noted the president has appeared to change his approach in recent weeks in case the Democratic nominee delivers a strong performance.

HOW TO WATCH THE FIRST PRESIDENTIAL DEBATE MODERATED BY FOX NEWS' CHRIS WALLACE

"There's been a big reversal in the past week on that tone and tenor and those phrases," Baier said, "and the campaign and even the president has been saying he's {Biden] done a lot of debates, he's been in Washington for 47 years, he steps up to the moment, so I think there's been kind of like the Fred Flintstone car running backwards, trying to make up for what was said prior to that.

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"But listen," Baier added, "it is different tonight. While Joe Biden has tried to make it about Donald Trump, this election -- this [debate] tonight, is about how Joe Biden shows up and how he deals with 90 minutes, six topics, 15 minutes each."