Former Democratic Rep. Tulsi Gabbard will assist Trump in preparing for his first debate against Vice President Kamala Harris.

"[Trump] does not need traditional debate prep but will continue to meet with respected policy advisors and effective communicators like Tulsi Gabbard, who successfully dominated Kamala Harris on the debate stage," Trump campaign National Press Secretary Karoline Leavitt wrote in a statement to ABC News, confirming a development first reported by The New York Times.

Gabbard, a former Democratic congresswoman from Hawaii and a one-time Democratic presidential candidate during the 2020 election, gained brief momentum during her presidential run after challenging Harris on the debate stage on topics like criminal prosecutions.

Since leaving the Democratic Party, Gabbard has been gaining traction among Trump supporters, and more recently she has appeared on Fox and other conservative news outlets attacking Harris.

– ABC News’ Rachel Scott, Soo Rin Kim, Kelsey Walsh, and Lalee Ibssa

The first debate between Vice President Harris and former President Trump will be held by ABC News at the National Constitution Center in Philadelphia.

The Sept. 10 debate will be moderated by ABC News anchors David Muir and Linsey Davis.

It will air live at 9:00 p.m. ET on the network and on its 24/7 streaming network ABC News Live, Disney+ and Hulu.

Prime-time convention programming will air live from the United Center in Chicago from 6:30-11 p.m. ET on Monday and 7-11 p.m. ET on Tuesday through Thursday.

Beyond the nominee acceptance speeches --vice presidential nominee Tim Walz on Wednesday and presidential nominee Kamala Harris on Thursday -- programming has not been finalized or announced yet.

It has been confirmed, however, that "current and past Presidents are expected to participate in convention programming." President Joe Biden, Former President Barack Obama and Bill and Hillary Clinton are all tentatively slated to speak at the convention, sources familiar have told ABC News.

Much of the rest of the schedule will be rolled out in the coming days.

High-profile political leaders are also expected to make remarks at the DNC's Constituency Caucuses and Councils meetings that will take place throughout the week. Celebrities are also expected throughout the week, with a number of big names announced already to participate in events adjacent to the convention, including John Legend, Jon Stewart, Billy Porter, Joan Jett, Octavia Spencer, DJ D-Nice and Lil Jon.

-ABC News' Isabella Murray and Brittany Shepherd

Robert F. Kennedy Jr. plans to appear in Pennsylvania and New York courts next week to defend himself in lawsuits, brought by Democrat-aligned groups, that challenge the validity of voter signatures he was required to gather to make the ballot as an independent candidate.

"Mr. Kennedy will now be testifying in court next week in Harrisburg, PA, on Tuesday and Mineola, NY, on Wednesday or Thursday to defend ballot access challenges," campaign spokeswoman Stefanie Spear told ABC News in a statement.

Spear added that RFK Jr.'s campaign has canceled its event in Chicago on Sunday and Monday next week in preparation of the court appearances.

The Pennsylvania case mirrors one that Kennedy lost this month in upstate New York, as it argues he listed on his nominating petition forms an address where he doesn’t live.

Plaintiffs in the Long Island case argue that contractors hired by the Kennedy campaign to gather signatures engaged in fraudulent activity, citing a New York Times piece in May that quoted voters who said Kennedy-aligned petitioners who approached them folded over the page to conceal Kennedy's name.

"We should make it very clear that nobody wanted this to happen and did everything they could to make it stop happening," William F. Savino, a lawyer representing Kennedy in the case, told ABC News Thursday.

"Nobody wanted improper signatures, and we had the luxury of so many extra signatures, there was no incentive to bend the rules or fold the paper," Savino added.

-ABC News' Will McDuffie