A combative Kamala Harris pledged a clean break from Joe Biden's presidency Wednesday in an interview with right-wing Fox News aimed at reaching Republican voters wary of Donald Trump.

Harris clashed with interviewer Bret Baier on hot-button issues including immigration and gender transition surgery, with the Democratic nominee repeatedly asking "may I finish" when the host talked over her answers.

A key moment in the half-hour sit-down came as Harris was being pressed on comments she made last week -- that Republicans have seized on -- when she said she could not think of anything she would have done differently from Biden during his four years in office.

"My presidency will not be a continuation of Joe Biden's presidency," said Harris, 59, who became her party's nominee after the aging Biden dropped out in July.

Harris said she would bring "fresh and new ideas" and added: "I represent a new generation of leadership."

Biden had said on Tuesday that Harris would "cut her own path" as president.

Harris also launched into a blistering attack on Republican former president Trump, 78, for threatening to use the military against internal enemies.

"He's the one who tends to demean and belittle and diminish the American people. He's the one who talks about an 'enemy within.'"

- Harris's gamble -

Responding on his Truth Social site, Trump said: "Again, congratulations to Bret Baier on a tough but very fair interview, one that clearly showed how totally incompetent Kamala is."

Harris's first-ever sit-down with Fox was a gamble as she seeks to break the deadlock in a White House race that remains neck-and-neck with less than three weeks to go.

The Democrat faced probing questioning during the interview, with Baier also asking her to respond to Trump campaign advertisements and a clip of the Republican defending his military remarks.

Harris repeatedly turned questions back to her election rival Trump.

Some of the testiest exchanges came as Baier pushed Harris on the record numbers of illegal immigrants who have crossed the Mexican border under the Biden administration. Numbers have dramatically fallen in recent months.

Harris replied by saying that the Biden-Harris administration had proposed a bill for greater border security but that "Donald Trump told (Republicans) to kill it."

Harris was also quizzed on gender surgery for prisoners or illegal aliens, a conservative attack angle used in a series of the Trump campaign's recent television ads.

"I will follow the law -- and it's a law that Donald Trump actually followed," Harris said, referring to a New York Times report Wednesday that under Trump's presidency, prisons also offered gender-affirming care.

Asked when she had first noticed that Biden's mental acuity had "diminished" before he quit the race following a disastrous debate with Trump, Harris again turned the subject back to the Republican.

"Bret, Joe Biden is not on the ballot. And Donald Trump is," she said. 

- 'Day of love' -

Fox News has played a key role in Trump's political rise, and he earlier blasted the network over the Harris interview, accusing Baier of being "very soft."

Trump on Wednesday responded to questions from Hispanic voters in Miami in a show aired by Univision, the biggest TV network serving Latino viewers in the United States.

He repeated attacks on migrants, claiming without evidence that people from foreign prisons and mental asylums were flooding into the country.

The Republican also called January 6, 2021 -- when his supporters stormed the US Capitol -- a "day of love," and once again cast doubt on the existence of climate change. 

The campaign will continue on Thursday, with a new podcast interview of Trump airing and Harris hitting the trail in the key swing state of Wisconsin.