The overturning of legal protections for abortion in the US marks "one of the darkest days for women's rights", Nicola Sturgeon has said.

Millions of women in the US will lose the constitutional right to abortion, after the Supreme Court overturned its 50-year-old Roe v Wade decision.

The judgement paves the way for individual states to ban the procedure, with around half expected to introduce new restrictions or bans.

Thirteen have already passed so-called trigger laws to automatically outlaw abortion.

Research from Planned Parenthood, a healthcare organisation that provides abortions, has estimated that access to abortions will be cut off for around 36 million women of reproductive age. 

Ms Sturgeon tweeted: "One of the darkest days for women's rights in my lifetime.

"Obviously the immediate consequences will be suffered by women in the US - but this will embolden anti-abortion and anti-women forces in other countries too.

"Solidarity doesn't feel enough right now - but it is necessary."

Green MSP Gillian Mackay, who has previously launched a private member's Bill to implement anti-abortion buffer zones outside hospitals and clinics across Scotland to protect women from pro-life campaigners, commented on the latest Supreme Court decision.

"This will only stop safe abortions and put lives at risk," she said.

"Solidarity to all those in the US.

"Here we need to continue to fight for progress.

"That means buffer zones, telemedical abortion and services safe and accessible for all."

Scottish Labour West Scotland MSP Katy Clark described the ruling as "a disgraceful decision" that "turns back the clock 50 years in women's rights."

Members of pro-choice group Back Of Scotland, which campaigns for safe buffer zones around places offering abortion services, said they were "absolutely devastated" by the Supreme Court's decision.

"They haven't eliminated the right to abortion, they have just eliminated the right to safe abortion," campaigners said.

"Abortions will still happen.

"They'll just happen in unsafe backstreet clinics.

"Women will die."

Labour MSP Monica Lennon, who recently wrote to the First Minister raising concerns over the rise in anti-abortion protests outside hospitals and clinics in Scotland, said: "A devastating day for women in the US and around the world.

"Our solidarity will be judged by our actions.

"Clinic harassment is a daily occurrence in Scotland.

"It cannot be tolerated."

Prime minister Boris Johnson said the decision was "a big step backwards".

"I have always believed in a woman's right to choose and I stick to that view, that's why the UK has the laws that it does," he said.

Referring to changes to the law in Northern Ireland, he added: "We recently took steps to ensure that those laws were enforced throughout the whole of the UK."

President Joe Biden described it as "a tragic error" and urged states to enact laws to allow the procedure.

Denouncing the Supreme Court ruling, President Biden told women in states where it was banned to travel to those where it was not.

The landmark 1973 Roe v Wade case saw the Supreme Court rule by a vote of seven to two that a woman's right to terminate her pregnancy was protected by the US constitution.

The ruling gave American women an absolute right to an abortion in the first three months (trimester) of pregnancy, but allowed for restrictions in the second trimester and for prohibitions in the third.