Trump says a presidential debate 'isn't something you have to practice' as candidates' first show-down approaches

President reportedly told aides debate are not something one has to prepare for, bucking decades of precedent

Joe Biden, the Democratic presidential nominee, will not be the subject of any debate prep for Donald Trump. He's going to wing their three debates. (AP)

Donald Trump signalled earlier this week he will not formally prepare for his three debates against Democratic foe Joe Biden, and a new report suggests he will wing each session on a bet the former vice president will trip himself with gaffes and forgetfulness.

The 74-year-old president for months has tried casting the 77-year-old Mr Biden as too old and mentally slow as he approaches 80 to be the so-called leader of the free world. He has tried sowing seeds of doubt into the minds of remaining undecided voters and key blocs he is trying to win back, like just enough suburban white women.

The president himself made the decision to skip a 2016-like debate preparation session, when former New Jersey Governor Christie played the role of former Secretary of State Hillary Clinton. Mr Christie had reportedly been tapped to play the role of Mr Biden, but it appears that will not happen.

A presidential debate“isn’t something you have to practice,” Mr Trump told aides, unnerving some of his closest advisers, NBC News reported.

He is set to go face-to-face with Mr Biden in a few weeks, and Mr Trump intends to wing it. He signalled just that during a wild 47-minute phone interview with “Fox & Friends,” his favorite right-leaning morning cable news and opinion show.

One of the hosts asked how he plans to prepare for the three debates. Mr Trump, notably, did not describe what are sometimes called “murder board” sessions with Mr Christie or another GOP figure mimicking Mr Biden. Instead, the president essentially said he is too busy getting back on the campaign trail to spend hours practicing canned spiels about policy proposals and witty attack lines for his opponent.

“Well, I sort of prepare every day by just doing what I'm doing. I was in California yesterday (Monday). I went to Arizona, which is doing great by the way, the state is doing, is booming. And done a really good job with the virus too, you know down to, it's down to, it's very low,” he said, sending a shoutout to one battleground state before mentioning another possible one that he has to hold to have any shot at a second term.

“An excellent governor, excellent in Texas,” Mr Trump said of ally Greg Abbott, also a Republican.

The president described campaign trips as the best kind of debate prep.

“I've been to Texas over the last few days, I've been to Louisiana, Florida, I mean, I've been all over the place,” he told Fox before slamming Mr Biden’s lighter schedule, which never seems to take him that far from his Delaware home.

“And I watch this guy (Biden) sitting home and I say, maybe I'm doing it wrong, you know what maybe I'm doing it wrong,” the president said mockingly.”

He also contended he cannot prepare for the debates because Mr Biden performed unevenly in the Democratic primary debates.

“Well, I don't know which Biden is going to show up because I watched him during the debates where they had 20 people on the stage and, you know, before they started calling it out, and I watched him and he was a disaster. You don't get worse, he was grossly incompetent,” Mr Trump alleged. “Then, I watched him against Bernie [Sanders] and he was okay. He wasn't Winston Churchill, I can tell you that, but he was okay.”