WASHINGTON, United States (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 the tight election going down to the wire, both candidates are on a mission to persuade the sliver of American voters who remain undecided in the home stretch.

In a dramatic campaign season, the latest twist was revelations by Trump’s longest-serving chief of staff, retired US Marine general John Kelly about the Republican’s admiration for the Nazi dictator and his military in World War II.

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

Harris was quick to respond, delivering a statement outside her vice presidential residence in Washington.

“It’s deeply troubling and incredibly dangerous that Donald Trump would invoke Adolf Hitler, the man who is responsible for the deaths of six million Jews and hundreds of thousands of Americans,” she said.

“All this is further evidence for the American people of who Donald Trump really is.”

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

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

Trump’s camp hit back, saying Harris is “desperate because she is flailing, and her campaign is in shambles.

“That is why she continues to peddle outright lies and falsehoods that are easily disproven,” Trump spokesman Steven Cheung said in a statement.

When asked whether President Joe Biden agrees with Kelly’s assessment that Trump is a fascist, White House spokesperson Karine Jean-Pierre was unequivocal.

“Do we agree about that determination? Yes we do,” she said.

Harris, 60, touched down in Pennsylvania Wednesday for a CNN town hall-type meeting near Philadelphia, but there is not one planned for Trump despite the network’s offer to host.

Pennsylvania is a coveted prize for the candidates, and Harris and Trump have made repeated appearances there and across other swing states.

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.

Trump will hold his own town hall Wednesday as well as a rally in the southern battleground state of Georgia, which the 78-year-old Republican won in 2016 and then narrowly lost to Biden four years later.

More than 24.5 million Americans have already voted by mail or in person, reportedly a far higher number than the same period four years ago.