US presidential candidate Donald Trump is set to meet face-to-face with Democratic nominee Kamala Harris on Tuesday to lay out their starkly different visions for the country after a turbulent summer of campaigning.

The event, which begins at 9 PM ET in Philadelphia, will provide Americans with a detailed look at a campaign that has changed dramatically since the last debate in June.

Chairperson of the Republican National Committee Michael Whatley revealed the state of presidential candidate Donald Trump hours before the upcoming debate with Democratic nominee Kamala Harris in their fierce battle for the presidency of the United States, according to ABC News.

Whatley said in an interview with the American network that Trump is "comfortable" and "relaxed" and "well prepared for the debate".

He added that it is unfair for the Harris campaign to say that Trump is going to lie during the debate tonight.

Whatley also said Trump would avoid using “personal attacks” in the debate, noting that the former president “wasn’t nervous before the debate at all.”

The debate comes eight weeks before the Nov. 5 election, a tight race that could easily be decided by either candidate.

Harris, for her part, is seeking to prove that she can make the Democratic case against Trump better than Biden.

Trump, for his part, is trying to portray the vice president as an out-of-touch conservative, while trying to win over voters who are skeptical that he should return to the White House.