Democratic presidential nominee Joe Biden is shining a spotlight on President Trump’s unpredictable nature.

Speaking with reporters Thursday morning before boarding a flight to campaign in the battleground state of Arizona, the former vice president was asked about the president’s insistence minutes earlier that he wouldn’t take part in a virtual presidential debate with Biden next week.

“You never know what's going to come out of his mouth,” Biden said.

TRUMP SAYS HE WON'T 'WASTE MY TIME' WITH A 'VIRTUAL DEBATE' WITH BIDEN

With Trump huddling in the White House after being diagnosed with COVID-19 last Friday and after being hospitalized for three days at Walter Reed National Military Medical Center for coronavirus treatments, the Commission on Presidential Debates (CPD) announced Thursday morning that the Oct. 15 scheduled second debate between the president and Biden would be held virtually, with both candidates taking part from separate remote locations.

The president quickly responded, telling Fox Business' Maria Bartiromo later Thursday morning that he would not take part in a virtual debate.

"The commission changed the debate style and that's not acceptable to us," Trump said on "Mornings with Maria."

"I'm not going to do a virtual debate," Trump added. "I’m not going to waste my time at a virtual debate."

Democratic presidential candidate former Vice President Joe Biden speaks to members of the media before boarding his campaign plane at New Castle Airport in New Castle, Del., Thursday, Oct. 8, 2020., en route to Arizona. (AP Photo/Carolyn Kaster)

Democratic presidential candidate former Vice President Joe Biden speaks to members of the media before boarding his campaign plane at New Castle Airport in New Castle, Del., Thursday, Oct. 8, 2020., en route to Arizona. (AP Photo/Carolyn Kaster)

Biden, when asked about Trump’s refusal to take part in the debate, responded, “We don't know what the president is going to do, he changes his mind every second so for me to comment on that now would be irresponsible. I think that if -- I'm going to follow the commission recommendations. If he goes off and he's going to have a rally, I'll -- I don't know what I'll do.”

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The second debate is scheduled to be a town hall-style format. The commission said Thursday morning that the moderator of the debate – C-SPAN’s Steve Scully – and the live audience would be at the debate hall in Miami, Fla., with Biden and Trump taking part remotely.

The first debate between Biden and Trump – which took place last week in Cleveland, Ohio, was plagued by incessant interruptions and insults. President Trump was the larger of the two culprits. According to a Fox News analysis, the president interrupted Biden and moderator Chris Wallace of "Fox News Sunday" a total of 145 times, with the former vice president interrupting Trump and Wallace 67 times.

Trump – on Thursday morning – once again claimed that "I beat him [Biden] in the first debate, I beat him easily."

A couple of hours after the former vice president's comments, Biden deputy campaign manager Kate Bedingfield charged in a statement that “Donald Trump clearly does not want to face questions from the voters about his failures on COVID and the economy. As a result, Joe Biden will find an appropriate place to take questions from voters directly on October 15th, as he has done on several occasions in recent weeks.”

And she added that “given the President's refusal to participate on October 15th, we hope the Debate Commission will move the Biden-Trump Town Hall to October 22nd, so that the President is not able to evade accountability. The voters should have a chance to ask questions of both candidates, directly. Every Presidential candidate since 1992 has participated in such an event, and it would be a shame if Donald Trump was the first to refuse.”