Hollywood star Jennifer Aniston has let rip at Republican vice presidential candidate JD Vance after his controversial comments about “childless cat ladies” went viral.

Aniston took to Instagram to blast Donald Trump’s running mate on Thursday (AEST), saying she “truly can’t believe” that Vance was in contention to become the next vice president of the US.

The Friends and Morning Show star posted a screenshot of a social media post of a 2021 TV interview clip with Vance. In it, the conservative Republican tells host Tucker Carlson that the US is run by “a bunch of childless cat ladies who are miserable at their own lives and the choices that they’ve made and so they want to make the rest of the country miserable, too”.

Vance then mentions Vice-President and Democrat presidential candidate designate Kamala Harris, US Transportation Secretary Pete Buttigieg and representative Alexandria Ocasio-Cortez.

“It’s just a basic fact – you look at Kamala Harris, Pete Buttigieg, AOC – the entire future of the Democrats is controlled by people without children,” he tells Carlson.

“How does it make any sense that we’ve turned our country over to people who don’t really have a direct stake in it?”

A fuming Aniston hit back on Thursday.

“I truly can’t believe this is coming from a potential VP of the United States,” she wrote.

“All I can say is … Mr Vance, I pray that your daughter is fortunate enough to bear children of her own one day. I hope she will not need to turn to IVF as a second option. Because you are trying to take that away from her, too.”

Aniston, 55, has previously been open about her own struggles with IVF. In 2022, she revealed she had tried for years through her 30s and 40s to have a baby.

“It was a challenging road for me, the baby-making road,” she said.

“All the years and years and years of speculation … It was really hard. I was going through IVF, drinking Chinese teas, you name it. I was throwing everything at it. I would’ve given anything if someone had said to me, ‘Freeze your eggs. Do yourself a favour’.

“So here I am today. The ship has sailed.”

Vance, 39, is a fire-brand conservative senator whose policies also include criminalising gender-affirming care for transgender children, supporting a 15-week cutoff for abortions, even in cases of rape or incest, and who has denounced divorce.

Trump takes aim at Harris

Aniston’s comments followed Vance’s would-be boss labelling Harris the “ultra-liberal driving force” who should be blamed for the Biden administration’s policies on immigration.

Trump addressed a North Carolina rally on Wednesday, three days after President Joe Biden abruptly dropped his re-election bid and endorsed Harris.

She has since pulled in broad support across the Democratic Party and revitalised its election campaign.

Trump tried to quash some of that momentum in an aggressive speech on Wednesday (local time), his first since Harris’ emergence changed the race.

“She is a radical left lunatic who will destroy our country if she ever gets elected,” he said.

Trump routinely uses insults in attacking his opponents and made clear he planned to ignore advice that he take a softer line.

“I’m not gonna be nice!” he told his cheering supporters in Charlotte.

Trump’s rally began two hours before Biden, 81, addressed Americans from the Oval Office to explain why he dropped out of the race under mounting pressure from fellow Democrats.

He said his withdrawal and endorsement of Harris was the best way to unite the US, despite his ambition to win a second term.

“Nothing, nothing can come in the way of saving our democracy. That includes personal ambition,” he said.

“I decided the best way forward is to pass the torch to a new generation. That is the best way to unite our nation.”

Harris, the first Black woman and Asian-American to be vice president, will become the first woman elected president if she wins on November 5.

-with AAP