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, Trump’s campaign and his surrogates continued to insinuate Monday that the former president’s strategy during the debate will be to link Harris to what they call her policy failures and “disasters” as leader of the Biden-Harris administration.

MORE: Harris-Trump ABC News Presidential Debate: How to Watch, What to Know

With time running out for the debate between the two candidates, both candidates are trying to influence expectations. This is expected to be a key moment for both campaigns as they look to attract voters ahead of what will likely be a close race in November.

In a radio interview with morning show host Rickey Smiley, Harris said, “We have to be prepared for him not to be charged with telling the truth.”

“And we have to be prepared for the fact that he’s probably going to tell a lot of untruths,” she said in the interview, recorded Wednesday while Harris was attending a rally in New Hampshire.

“I think he’s going to lie,” she said.

MORE: What the Polls Say Ahead of the Harris-Trump Presidential Debate

At a press conference for the Trump campaign and the Republican National Committee on Monday afternoon, Karoline Leavitt, the Trump campaign’s national spokesperson, said Harris “will finally be forced to defend her record” on issues like crime and the border.

Trump campaign senior adviser Jason Miller claimed that Harris is the one running the White House, not President Joe Biden, and that other major events, such as the derailment in East Palestine, Ohio, or the wildfires in Maui, Hawaii, are her responsibility: “Kamala Harris is responsible for all of these disasters.”

Later, responding to a question about the tone Trump would take with Harris, Miller said Trump “will be himself.”

The ABC News debate, moderated by David Muir and Linsey Davis, will take place Tuesday, September 10 at 9 p.m. ET. A primetime 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 about establishing her presence and redefining herself to voters, she now wants to prioritize attacking Trump’s policies and grilling him during the debate.

Harris told Smiley that she “plans to(S) to point out that Trump “tends to fight for himself, not for the American people.”

Harris’ campaign has also noted that this is new territory for Harris, as this is her first-ever presidential debate, compared to what will be Trump’s seventh. This is the first time the two have gone head-to-head.

Harris will remain in Pittsburgh, holding mock debates on a lighted stage at her hotel to boost the atmosphere on Tuesday.

She also relies on many of the advisers who groomed Hillary Clinton in 2016, including Philippe Reines, who is replacing Trump and is approaching his role as a “method actor”: According to one source, he plays Trump while wearing a wig.

MORE: Where Harris and Trump Stand on Key Issues

The Trump campaign is aware of Harris’ extensive debate preparation. Former Democratic Rep. Tulsi Gabbard, who is advising Trump on the debate, said Monday on “Fox and Friends” that “Harris should not be underestimated” given her “good” debate preparation.

“She takes this debate seriously,” Gabbard said. “She comes prepared with memorized lines, ready to recite them and deliver them in a way that I think is very effective.”

Gabbard said Trump “doesn’t have to prepare” like Harris, and that he has instead prepared in unconventional ways, such as addressing the American people through interviews and town hall meetings.

Gabbard added that Harris’ record speaks for itself and that Trump is “very focused on the issues.” He will emphasize her role as a sitting 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.

According to the sources, Gaetz has asked Trump questions about a number of difficult issues, including his legal troubles.

Watch the latest stories and videos from the presidential debate from ABC News here.

ABC News’ Emily Chang, Soo Rin Kim, Kelsey Walsh and Lalee Ibssa contributed to this report.