Donald Trump attended a Supreme Court hearing on the legality of his executive order ending birthright citizenship in person - a historic first for a US president.

The court is hearing Mr Trump's appeal of a lower court ruling that struck down his directive ending automatic citizenship for children born to parents who are in the US illegally or temporarily.

Mr Trump sat in the first row of the public section of the court room for the hearing on Wednesday.

His presence in the court room made him the first sitting president to attend oral arguments at the nation's highest court.

A definitive ruling on the executive order, which Mr Trump signed on the first day of his second term to bring down immigration, is expected early in the summer.

The case poses another test to Mr Trump's assertion of executive power, with the US president reacting furiously when the court has ruled against him in the past.

Birthright citizenship is the first of Mr Trump's immigration-related policy to reach the court for a final ruling.

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Mr Trump issued a pre-emptive attack on the Supreme Court justices on Sunday, writing on Truth Social: "Birthright Citizenship is not about rich people from China, and the rest of the World, who want their children, and hundreds of thousands more, FOR PAY, to ridiculously become citizens of the United States of America. It is about the BABIES OF SLAVES!,"

He added: "Dumb Judges and Justices will not a great Country make!"

Just before Wednesday's hearing began, crowds watched on as Mr Trump's motorcade drove along Constitution and Independence Avenues, passing the Washington Monument, on the way to the court building.