Boris Johnson has branded a US Supreme Court judgement to deny legal abortion rights to millions of women as a "big step backwards".
The Prime Minister weighed in over the court's decision to strike down Roe v Wade, which will allow individual states to ban terminations.
The landmark 1973 judgement recognised a woman's constitutional right to abortion and legalised it nationwide.
But justices today overturned the ruling after deciding the original judgement was wrong because the U.S. Constitution makes no specific mention of abortion rights.
It is expected to lead to abortion bans in roughly half of US states.
The seismic move immediately triggered waves of anger across the globe, and campaigners from both sides took to the streets in Washington.
The Prime Minister waded into the row at a press conference in Kigali, Rwanda, where he is attending the Commonwealth Heads of Government Meeting (CHOGM).
Asked about the decision, Mr Johnson said: "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."
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."
It is unusual for politicians to comment on legal systems in countries the UK considers to be allies, but his words underline the global reach of the decision.
Mr Johnson is likely to cross paths with US President Joe Biden at diplomatic summits next week.
The British Pregnancy Advisory Service (Bpas), the UK's leading abortion provider, said it is "appalled" by the news.
Chief executive Clare Murphy said: "Banning abortion does not remove women's need to end a pregnancy. It simply makes it more difficult and more dangerous."
She called on the British Government to condemn the "assault on women's human rights", adding: " "For our politicians to watch silently as women's rights are rolled back would be unforgivable."
Nimco Ali, the Government's independent adviser on tackling violence against women and girls, called the decision "an assault on women's human rights, their lives and their families".
She tweeted: "The UK Government and other #G7 cannot remain silent as women's human rights are breached."
The Women's Equality Party tweeted: "Make no mistake. Women will die because of this ruling, and tens of thousands more will be criminalised or forced to continue with pregnancies they did not choose.
"It is barbaric, inhumane and utterly heartbreaking. Solidarity with our sisters."
London Mayor Sadiq Khan tweeted: "London stands with the women of America whose most basic rights and freedoms are threatened by this ruling.
"A dark day for a great country."
