“The day I left, we had the most secure border in the history of our country,” Trump told his supporters midway through his more than 90-minute speech, citing his support from a major border patrol union.

“I shouldn’t have gone,” he added, “because we did so well.”

Trump lost the 2020 election to President Joe Biden by 74 Electoral College votes. The Republican presidential candidate has long made allegations of voter fraud that impacted his race. Courts across the country have all rejected these allegations. Trump is also being prosecuted and charged at the state level in Georgia over his alleged attempts to overturn the election results.

More: Trump supporters expect election fraud and violence

Trump has not said whether he will accept the outcome of the 2024 race against Vice President Kamala Harris if he loses.

During his rally in Pennsylvania, Trump repeated baseless claims of voter fraud and questioned common voting procedures, including absentee voting and early voting.

“They’re fighting so hard to steal this damn thing,” Trump said without evidence. “They’re talking about extending working hours… Who’s ever heard of that?”

A Pennsylvania judge last week extended the deadline for voters in Bucks County to request an absentee ballot. The ruling was in response to a Trump campaign lawsuit alleging long lines prevented some of the former president's supporters from voting.

Trump and RNC step up voter fraud allegations in key Pennsylvania counties

“They cheated.” Donald Trump is already amplifying unconfirmed claims of voter fraud in key Pennsylvania counties.

Election officials in some other counties across the country have proposed adding additional early morning voting times to curb long lines to vote.

The former president also ramped up rhetoric against journalists in his speech on Sunday. Trump pointed to the protective glass surrounding him and said a would-be assassin would have to shoot through the news media to hit him.

“To get me, someone would have to shoot through the fake news. And that doesn't bother me that much. I don’t mind,” he said.

Trump campaign spokesman Steven Cheung said the president's comments were not about the press but rather about his personal safety in light of the two assassination attempts against him earlier this year.

“The President's statement about the placement of protective glass has nothing to do with harming the media or anything else. “It was about threats against him that were incited by dangerous rhetoric from Democrats,” Cheung claimed in a statement.

“President Trump stated that the media was in danger by protecting him and therefore was in grave danger itself and should have had a glass shield as well,” he added.

Trump's comments come as both presidential campaigns have faced criticism in recent days for their heightened and sometimes violent political rhetoric. Last week, Trump suggested that guns should be aimed at former Rep. Liz Cheney, R-Wyo., who has endorsed Harris and become one of the former president's most vocal GOP critics.

Biden received criticism earlier this week for appearing to call Trump supporters “trash,” although he said he was referring to racist remarks made by a comedian at the former president's rally at Madison Square Garden.