Kamala Harris pressed a forceful case against Donald Trump in their first and perhaps only debate before the presidential election, repeatedly needling him in an event that showcased their starkly different visions for the country on abortion, immigration and American democracy.

The Democratic vice president seemed to get under the skin of the Republican former president, provoking him with reminders about the 2020 election loss he still denies, mocking his rally crowds and delivering derisive asides at his other false claims.

Mr Trump labelled his rival as too liberal and questioned why she was proposing ideas she had not accomplished while serving as vice president, launching into the sort of freewheeling personal attacks and digressions from which his advisers and supporters have tried to steer him away.

Ms Harris promised tax cuts aimed at the middle class and said she would push to restore a federally guaranteed right to abortion overturned by the Supreme Court two years ago.

The former president said his proposed tariffs would help the US stop being cheated by allies on trade and said he would work to swiftly end the Russia-Ukraine war, although he twice refused to say he wanted Ukraine, which bipartisan majorities in Congress have backed, to win the war.

Ms Harris’ performance seemed to be the opposite of President Joe Biden’s in June, with sharp, focused answers designed to showcase the contrast between her and Mr Trump, using her body language and facial expressions to confront her rival and express that she found his answers ridiculous or amusing — or both.

In one moment, she turned to Trump and said that as vice president, she had spoken to foreign leaders who “are laughing at Donald Trump,” and said she had spoken to military leaders “and they say you’re a disgrace.”

As Mr Trump, 78, again questioned her racial identity, 59-year-old Harris, the first woman, black person and person of South Asian descent to serve as vice president, pointedly gestured to Trump and responded: “I think the American people want better than that, want better than this.”

Mr Trump in turn tried to link Ms Harris to Mr Biden, questioning why she had not acted on her proposed ideas while serving as vice president, focusing his attacks on her assignment to deal with the root causes of illegal migration.

He repeatedly dismissed her and Biden as weak and cited the praise of Hungary’s nationalist prime minister Viktor Orban to show he is a widely respected by leaders around the world.

Mr Trump again denied that he lost to Mr Biden four years ago, when a mob of his supporters stormed the US Capitol to try to stop the certification of his loss based on false or unsubstantiated claims of voter fraud.

“Donald Trump was fired by 81 million people,” Ms Harris said, “So let’s be clear about that. And clearly he is having a very difficult time processing that.”

Her campaign ended the debate by expressing openness to another meeting in October — and welcomed an endorsement from megastar Taylor Swift, who labelled herself a “childless cat lady” in a dig at Mr Trump’s running mate, Ohio Senator JD Vance, as she encouraged her fans to vote.

Saying it’s “time to turn the page,” Ms Harris delivered an appeal to Republicans and independents turned off by Trump’s style and his efforts four years ago to overturn the 2020 presidential election, saying there is a place in her campaign for them “to stand for country, to stand for our democracy, to stand for rule of law and to end the chaos”.

She sharply criticised Mr Trump for the state of the economy and democracy when he left office after his supporters stormed the Capitol on January 6 2021 in a bid to overturn the 2020 presidential election.

She laid the end of a federally guaranteed right to abortion at Mr Trump’s feet for his role in appointing three US Supreme Court justices who overturned Roe v. Wade, leaving more than 20 states in the country with what she called “Trump abortion bans.”

Ms Harris gave one of her most impassioned answers as she described the ways women have been denied abortion care and other emergency care since that ruling, and said Mr Trump would sign a national abortion ban if he wins.

Trump declared it “a lie,” and said, “I’m not signing a ban and there’s no reason to sign a ban.”

The Republican has said he wants the issue left to the states.

Ms Harris responded to a question about her plans to improve the economy by saying she would extend the tax cut for families with children and a tax deduction for small businesses while attacking Trump’s plans to impose broad tariffs as a “sales tax” on goods that the American people will ultimately pay.

The former president was stone-faced during her answer but retorted: “I have no sales tax. That’s in incorrect statement. She knows that.”

Mr Trump attacked Harris for the inflation seen under the Biden-Harris administration, a major liability for the vice president. He quickly turned his answer to warning about immigrants coming into the country — one of the subjects he’s focused on most heavily in his campaign.

He called his proposed tariffs a straightforward way to make other countries pay up for what he has long argued is an imbalance that hurts the US.

Throughout his campaign, Mr Trump has leaned on illegal immigration and accused Democrats of abetting large numbers of unauthorized crossings.

But as he often does in his rallies and on his social media account, he reeled off a series of falsehoods or unproven claims about migrants – alleging Haitian immigrants in an Ohio town are hunting and eating pets. Officials in Springfield, Ohio, say they have no evidence of that happening.

He Trump also twice declined to say that it was in the best interest of the US for Ukraine to win its war against Russia.

Ms Harris said it was an example of why America’s Nato allies were thankful he was no longer in office, as she and Biden have sent tens of billions of dollars to help Kyiv fend off Russia’s invasion.

The former president at one point launched into an attack on Mr Biden, questioning his mental acuity by making the claim that Biden “doesn’t even know he’s alive.”

His rival quickly tried to turn it around to make Mr Trump look less than sharp.

“First of all, I think it’s important to remind the former president, you’re not running against Joe Biden. You’re running against me,” she said.