Philadelphia (AFP) - Kamala Harris on Wednesday said Donald Trump was “increasingly unhinged” and called her US election rival’s reported praise for Adolf Hitler “incredibly dangerous,” as campaigning intensified ahead of the November 5 vote.

The Democrat’s fierce criticism came as she headed to must-win Pennsylvania to face voters’ questions in a town hall and as Trump campaigned in battleground Georgia.

With polls suggesting a tight election in its final stretch, the vice president also unveiled plans for a “closing argument” rally on Tuesday at the Washington site where Trump addressed supporters before they stormed the US Capitol on January 6, 2021.

Harris’s comments on Trump were provoked by revelations from his longest-serving chief of staff, John Kelly, who discussed the Republican’s praise for the Nazi dictator and his military in World War II.

The decorated Iraq veteran told The New York Times that Trump remarked that “Hitler did some good things too” and that instead of the US military, he “wanted generals like Adolf Hitler had.”

With Trump’s rivals raising concerns about his willingness to honor American democracy, Kelly also repeated his warning that he believes his ex-boss “certainly falls into the general definition of fascist.”

Harris told reporters outside her vice presidential residence in Washington that Trump’s alleged conduct was “deeply troubling and incredibly dangerous.”

“Donald Trump is increasingly unhinged and unstable, and in a second term, people like John Kelly would not be there to be the guardrails,” she said.

Trump hit back at a rally in Georgia, a key swing state the 78-year-old Republican won in 2016 and then narrowly lost to President Joe Biden four years later.

He attacked Harris over her economic policy and dusted off his catchphrase from his days on NBC reality TV show “The Apprentice” as he exhorted the crowd in Duluth to tell Harris: “You’re fired!”

“You have to stand up and you have to tell Kamala Harris that, ‘Kamala, you’ve done a horrible job. You’re the worst ever. There’s never been anybody like you… Kamala, you’re fired. Get out,’” he thundered.

- Trump accused -

Moments before Trump was due to take the stage, The Guardian newspaper reported a former model’s allegations that he groped her after the two were introduced by sexual abuser Jeffrey Epstein in the 1990s. Forty minutes into his speech, he had not addressed the claim.

Harris, 60, touched down in Pennsylvania ahead of a Wednesday prime-time CNN town hall-type meeting near Philadelphia, stopping at the Famous 4th Street Delicatessen to fist-bump employees and take selfies with patrons.

“Knock wood, God willing, we are going to win,” she said to cheers.

Some 26.5 million Americans have already voted by mail or in person, more than a million of them in Pennsylvania.

The Keystone State is a coveted prize for the candidates, and Harris and Trump have made repeated appearances there and across other swing states that decide US elections.

The Harris camp has also confirmed that Michelle Obama will join her at an event Saturday in battleground Michigan, the former US first lady’s debut campaign stop with Harris.

It will follow Harris’s first campaign appearance with former president Barack Obama, on Thursday in Georgia’s largest city Atlanta, as part of a major Democratic get-out-the-vote effort.

Veteran rocker Bruce Springsteen is set to kick off the event with a concert.

Harris’s sudden entry into the election campaign in late July shook the country, which was expecting a rematch between Biden and Trump, now a felon convicted on 34 charges of falsifying business records to hide hush-money payments to a porn star.

While Trump hammers home his promises of a migrant crackdown and economic good times after a period of high inflation, the Harris campaign has targeted his mental and physical fitness for the Oval Office while she courts moderate Republican voters.