Five of the justices, including Chief Justice Roberts, agreed that Trump’s executive order violates the Constitution’s 14th Amendment. Justice Brett Kavanaugh wrote separately to say believes the order is in violation of federal law.

On Truth Social, Trump said that the court’s decision was “too bad” and vowed to continue to fight to end birthright citizenship through legislation.

“No long and unwieldy constitutional amendment is necessary,” he said. “Congress should today start work on ending expensive, and unfair to our country, birthright citizenship.”

The US has granted citizenship to everyone born in the country since 1868, with the right enshrined in the 14th Amendment of the US Constitution, and bolstered by later US Supreme Court rulings.

Passed in the aftermath of the US civil war, the 14th Amendment – which was originally intended for recently freed slaves – reads that “all persons born or naturalised, and subject to the jurisdiction thereof, are citizens of the United States”

“Citizenship, then and now, was the right to have rights – to freely participate in our political community,” Justice Roberts wrote in the majority opinion. “The Framers of the Fourteenth Amendment extended that promise to ‘every free-born person in this land’,” he wrote.

“We keep that promise today,” the chief justice said.

The Trump administration argued that the “jurisdiction thereof” mentioned in the 14th Amendment should exclude children of people who do not live in the country permanently.

Three of the court’s nine justices dissented from the decision: Justices Clarence Thomas, Neil Gorsuch and Samuel Alito.

Justice Thomas argued that the 14th amendment was being “repurposed for political projects” and that the freed slaves it was originally intended for “were Americans” with no allegiance to other countries.

Another of the dissenting Justices, Samuel Alito, described the ruling as a “serious mistake” that “confers citizenship on virtually anyone who happens to be born in this country”, including those who come to the US with the explicit purpose of giving birth to a child and then returning to their country of origin.

The case was of enormous significance to President Donald Trump, who made a brief but historic appearance at the court to watch oral arguments in April.

On X, White House Chief of Staff Stephen Miller – a vocal proponent of stricter immigration rules – called it “one of the most destructive and outrageous decisions” in the Supreme Court’s history.

“American citizenship is not the birthright of the world,” he said. “No provision of the Constitution can be read to require our national self-obliteration.”

But immigration advocates and detractors of the administration celebrated the ruling.

Hakeem Jeffries, who leads Democrats in the US House of Representatives, said that by applying the law and being guided by the Constitution, the top court “finally affirmed that all persons born in the United States are American citizens”.

“There is, and shall be, no question,” Jeffries said.

Dariely Rodriguez, chief counsel at the Lawyers’ Committee for Civil Rights Under Law, said that the ruling “solidifies what we have known to be true for over a hundred years”.

“Anyone born on American soil, regardless of the legal status of their parents, is born an American citizen,” she added. We have endured an incredible test of our collective will as a nation and have prevailed.”