Trump-Harris debate live updates: High-stakes showdown just hours away

In an interview Tuesday with ABC News' Kyra Phillips, Republican National Committee Chairman Michael Whatley said it was unfair of the Harris campaign to suggest Trump would lie on stage tonight.

He also confirmed that Trump will stray away from personal attacks, and that the former president was not nervous.

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RNC chairman talks about tonight's critical debate

RNC chairman Michael Whatley speaks about the positive momentum going into tonight's debate for Trump and the unity the Republican Party has despite some not supporting the party's nominee.

"He feels very comfortable. He's rested, he's relaxed, and he's definitely ready to go," Whatley said.

Whatley also said "this is the most united the Republican Party has been in generations."

– ABC News’ Kelsey Walsh

The Trump campaign's debate watch party in Philadelphia tonight will take form in a fundraiser with Sen. JD Vance headlining the event, according to sources and an invitation obtained by ABC News.

The invitation doesn't detail the location, other guests or speakers of the night.

Tickets range from $5,000 to $50,000, with a photo opportunity costing $15,000 and a VIP ticket costing $25,000, the invitation shows.

-ABC News' Soo Rin Kim, Hannah Demissie, Lalee Ibssa, and Kelsey Walsh

There are no rules requiring Harris and Trump to shake hands before or after the debate.

If they do, it would mark the first time since 2016 that the candidates have shaken hands. Trump and Biden did not shake hands during their two matchups in 2020.

Trump contracted COVID-19 following the first debate.

The two candidates also didn't shake their hands during the June debate.

The Trump campaign during a pre-debate call said Trump is in "good spirits" and will be departing shortly for Philadelphia.

"President Trump is in good spirits. He is currently in Mar-a-Lago. My understanding is that he will be departing shortly to head over to Philadelphia," said Trump campaign senior adviser Danielle Alvarez when asked about his mood going into the debate.

She suggested that the former president is "ready" to talk about inflation, housing affordability and the border among other issues on the debate stage. Alvarez also suggested that Trump might attack Harris for flip-flopping on some key issues such as fracking, police funding and electric vehicles.

"The president is certainly full of surprises. I know that we can expect him to be, you know, with his, his charming self. We know that he is incredible when it comes to weaving in and out of topics -- he's incredible on those policy issues. So that's ... certainly something that may happen," she said.

-ABC News' Soorin Kim, Lalee Ibssa and Kelsey Walsh