Donald Trump preparing for debate with help from Matt Gaetz, Tulsi Gabbard: Sources

Former President Donald Trump's advisers may have publicly insisted he doesn't need any debate prep, but the former president is preparing more than he's letting on, sources tell ABC News.

Trump is holding informal policy sessions with a small team of advisers, including GOP Rep. Matt Gaetz and former Democratic Rep. Tulsi Gabbard, who once challenged Vice President Kamala Harris on the debate stage in 2019, the sources said.

Gaetz has been firing questions at Trump around some of the more challenging issues, such as his legal troubles, including his federal indictments on election interference and retaining classified documents, criminal conviction in the New York hush-money case and stance on abortion, according to the sources.

Two people familiar with Trump's preparation also told ABC News that Trump has been briefed on Harris' past debates, including the headline-making moment when she hit back at former Vice President Mike Pence with the words, "Mr. Vice President, I’m speaking." That exchange went viral then, and Trump has privately told his allies he won't let that happen to him.

Sources told ABC News that Trump's recent press address on Friday has left some on the GOP side with pre-debate concerns.

While Trump has continued with his campaign schedule, his movements on Friday puzzled some Republicans. Trump, following his appeal of the $5 million a federal jury awarded writer E. Jean Carroll after finding him liable for sexually assaulting and defaming her, came before the cameras rattling off -- in often vivid detail -- the accusations of sexual misconduct from multiple women over the years. All of which he has denied.

Meanwhile, as ABC News previously reported, Harris has been engaged in traditional debate prep in Pittsburgh.

The cameras caught her in the city on Sunday on a walk with second gentleman, Doug Emhoff. But, she ignored two shouted questions on Trump's claims that he’ll jail his political opponents and how she plans to respond to personal attacks from Trump on the debate stage.

On Saturday, Trump posted on TruthSocial, writing, "… the 2024 Election, where Votes have just started being cast, will be under the closest professional scrutiny and, WHEN I WIN, those people that CHEATED will be prosecuted to the fullest extent of the Law, which will include long term prison sentences so that this Depravity of Justice does not happen again."

Trump's false claims of election fraud in the 2020 election have continually been disproven.

Harris, on Sunday, did respond to a third question shouted at her by the media about whether she was ready by echoing, "ready," and giving a thumbs up before disappearing around the side of a building.

In related news, Trump's running mate, Sen. JD Vance, will appear in the spin room following the debate, ABC News has confirmed.

The ABC News presidential debate will take place on Sept. 10 at 9 p.m. ET and air on ABC and stream on ABC News Live, Disney+ and Hulu.