US Vice President Kamala Harris sought to make Donald Trump the face of Florida's strict new abortion ban Wednesday as Democrats hammer the issue ahead of November's presidential election.

"Across our nation, we witness a full-on assault, state by state, on reproductive freedom. And understand who's to blame: former president Donald Trump did this," Harris said in a Jacksonville, Florida speech.

Florida's harsh new ban took effect Wednesday, outlawing all abortions after six weeks of pregnancy in a state that had been one of the last in the southern United States with a relatively high gestational limit.

Trump, the presumptive Republican presidential nominee, has bragged about how justices he nominated allowed the conservative-leaning US Supreme Court to revoke the national right to abortion in 2022, in turn paving the way for 21 states to bring in total or partial bans.

The Florida ban took effect as Arizona's senate -- controlled by Republicans -- voted to repeal an 1864 law banning abortion, a month after the state's top court said the Civil War-era rule was still valid.

US President Joe Biden had earlier slammed the "extreme" Florida ban in a statement, and like Harris pinned the blame on the man he likely faces in a bitter rematch in November.

"There is one person responsible for this nightmare: Donald Trump," he said.

But it is Harris, the first female, black and South Asian vice president in American history, who has led the charge on a divisive subject that Democrats hope will be a vote winner in the 2024 election.

Harris, 59, who has become the campaign's leading voice on abortion rights, repeatedly used the phrase "Trump abortion bans" as she tried to tie the Republican to the issue.

Supporters in Jacksonville booed and cried "shame" on several occasions that she mentioned his name.

"Donald Trump is the architect -- and by the way, that is not a fact he hides. In fact he brags about it," she said, pointing to how Trump has repeatedly claimed credit for the Supreme Court decision.

- 'Very dark day' -

The Sunshine State's strict new law replaces a 15-week ban and has left women and clinics across the US South scrambling for options.

"Florida used to be a safe haven for abortion in the southern United States, so today is a very dark day in Florida's history," Ryan Moran, a nurse and abortion clinic volunteer, told AFP in Jacksonville.

"As of today, folks in Florida, if you’re seeking abortion services you will have to travel many states away."

Harris meanwhile slammed Trump for saying in an interview with Time magazine published Tuesday that states had the right to monitor women's pregnancies to enforce abortion bans.

Harris, who like Biden struggles with low approval ratings ahead of the election, added that a "second Trump term would be even worse" and said the Republican would sign a national abortion ban if elected.

Trump has recently fudged on the abortion issue amid signs it is hurting him in the polls. He repeatedly told Time it was up to states to decide, when asked if he would support a nationwide federal abortion ban.

By going to Florida the Democrats are taking the abortion fight right into Trump's backyard, as the scandal-tainted former commander-in-chief spends much of his time at his Mar-a-Lago resort in the state.

Florida has voted Republican since Trump's 2016 election victory, and its six-week abortion ban is the brainchild of Republican Governor Ron DeSantis.

The conservative DeSantis, who unsuccessfully ran against Trump for their party's presidential nomination this year, signed into law in April 2023 a bill to lower the limit from 15 weeks to six weeks.

The state's supreme court dismissed a final legal challenge by pro-abortion groups last month, paving the way for the ban to take effect.

But Florida voters will have a chance to reverse the six-week limit in a referendum that will coincide with November's election.