Donald Trump has called Philadelphia "one of the most egregious" places in the world during a rally in the city.

The former president and presumptive Republican nominee for the 2024 presidential election held a rally at Temple University's Liacouras Center in the Pennsylvania city on June 22 as part of his election campaign.

Pennsylvania, a key swing state, elected Joe Biden in 2020 by about 80,000 votes after electing Trump in 2016 and breaking its 24-year blue streak.

Only twice between 1932 and 1988 has a presidential candidate won the White House without also winning Pennsylvania, and no Democrat has been elected president without the state since 1948.

During his 85-minute speech, Trump repeated unproved claims about election fraud in the state in 2020 and said fraud had been "egregious" in Philadelphia.

"We cannot let this happen again," Trump said. "And Philadelphia was one of the most egregious places anywhere in the world—what happened in city, what happened in this city. So now they used COVID to cheat, they used a lot of things to cheat, but we're not going to let it happen again."

Biden's election campaign posted a clip of Trump making the comments on social media.

In response to a request for comment, Steven Cheung, Trump's communications director, told Newsweek: "Another cheap fake from the Biden campaign. He was clearly talking about election integrity from 2020."

Elsewhere in the speech, Trump said he liked the city and that he had gone to school there.

Trump's comments about Philadelphia follow reports that he called a Wisconsin city "horrible" during a closed-door meeting with GOP lawmakers at the U.S. Capitol earlier this month.

The meeting was a precursor to the Republican National Convention, set to take place in Milwaukee from July 15 to 18, where Trump is expected to be chosen as the party's nominee. According to Jake Sherman, a founder of the online political news daily Punchbowl News, the Republican attacked the convention's location, saying, "Milwaukee, where we are having our convention, is a horrible city."

Cheung denied the report on X, formerly Twitter. He wrote: "Wrong. Total bull****. He never said it like how it's been falsely characterized as. He was talking about how terrible crime and voter fraud are."

Nevertheless, experts said the reports could alienate voters, which may be damaging as polls ahead of the presidential election remain tight.

On June 27, Biden and Trump are set to square off in Atlanta for the first of two scheduled debates ahead of the general election on November 5.