Harris warned that Trump will lie during the pair's first head-to-head match.
CHICAGO -- Vice President Kamala Harris said in an interview that aired Monday that she expects former President Donald Trump to lie during the ABC News presidential debate on Tuesday.
Meanwhile, the Trump campaign and surrogates continued to insinuate on Monday that the former president's strategy at the debate will be to tie Harris to what they say are her policy failures and "disasters" as a leader of the Biden-Harris administration.
LIVE BLOG: Donald Trump vs Kamala Harris Presidential Debate
With time ticking down until the two meet for the debate, both candidates are working to spin expectations in what is expected to be a key moment for both campaigns as they look to appeal to voters ahead of what's expected to be a close contest in November.
In a radio interview with morning show host Rickey Smiley, Harris said "we should be prepared for the fact that he is not burdened by telling the truth."
"And we should be prepared for the fact that he is probably going to speak a lot of untruth," she said in the interview recorded Wednesday while Harris was at a rally in New Hampshire.
"I think he's going to lie," she said.
MORE: Harris-Trump ABC News presidential debate: How to watch, what to know
During a press call held by the Trump campaign and the Republican National Committee on Monday afternoon, Trump Campaign National Press Secretary Karoline Leavitt said Harris "will finally be forced to defend her record" on issues such as crime and the border.
Trump Campaign Senior Adviser Jason Miller claimed Harris is the one running the White House -- not President Joe Biden -- and so other major happenings such as the East Palestine, Ohio, derailment or the Maui, Hawaii, wildfires are on her: "every single one of these disasters are on Kamala Harris."
Later, responding to a question about the tone Trump will take with Harris, Miller said Trump is "going to be himself."
The ABC News debate, moderated by David Muir and Linsey Davis, will take place on Tuesday, Sept. 10 at 9 p.m ET. A prime-time pre-debate special will air at 8 p.m. ET. It will air on ABC and stream on ABC News Live, this station, Disney+ and Hulu. Viewers can also stream the debate on the ABC app on a smartphone or tablet, on ABC.com and connected devices.
While Harris' strategy has been focused on establishing her presence and redefining herself for voters, she now plans to prioritize attacking Trump's record and getting under his skin during the debate.
Harris told Smiley that she "intend[s] to point out" that Trump "tends to fight for himself, not for the American people."
The Harris campaign has also noted that this is new territory for Harris as it marks her very first presidential debate, compared to what will be Trump's seventh. This is the first time the pair have ever faced off against each other.
Harris continues to hunker down in Pittsburgh, engaging in mock debates on a stage with full lighting that has been established in her hotel to help stimulate Tuesday's environment.
MORE: What the polls say ahead of the Harris-Trump presidential debate
She is also relying on many of the advisers who helped prepare Hillary Clinton in 2016, including Philippe Reines who stands in for Trump and approaches his role like a method actor -- playing the part of Trump while wearing a wig, according to a source.
The Trump campaign is aware of Harris' extensive debate preparation -- with former Democratic Rep. Tulsi Gabbard, who is advising Trump on the debate, saying on "Fox and Friends on Monday that "Harris should not be underestimated" given her "solid" debate prep.
"She's taking this debate seriously," Gabbard said. "She will come prepared with memorized lines, ready to recite and deliver them in what I think, a very effective way."
Gabbard said Trump "doesn't need to" prepare like Harris, and he has instead engaged in nontraditional prep that includes speaking to the American people through interviews and town halls.
MORE: Where Harris, Trump stand on key issues
Gabbard added that Harris' record speaks for itself and that Trump is "very much focused on the issues." He will emphasize her role as the incumbent vice president leading the current administration.
Still, the former president is preparing more than he's letting on, sources told ABC News. Trump is holding informal policy sessions with a small team of advisers, including Gabbard and Republican Rep. Matt Gaetz.
Gaetz has been firing questions at Trump around some of the more challenging issues, such as his legal troubles, according to the sources.
Take a look at the latest stories and videos about the ABC News presidential debate here.
ABC News' Emily Chang, Soo Rin Kim, Kelsey Walsh and Lalee Ibssa contributed to this report.