The US Supreme Court has said that President Donald Trump can use $2.5bn (£2bn) of Pentagon funds for a section of wall on the southern border.
The court ruled by five votes to four to block a ruling by a federal judge in California that barred the president from spending the money on the wall.
The wall, dividing the US and Mexico, was Mr Trump’s major campaign promise during the 2016 election.
It is fiercely opposed by Democrats.
The decision by the Supreme Court means that the money will be used for wall projects in California, Arizona and New Mexico.
The court in California had argued that Congress had not specifically authorised the funds to be used for constructing the wall.
The President has argued that a new wall would help to curb illegal immigration, which he says is fuelling crime and placing a strain on the economy.
Democrats say they are in favour of border security but the wall would be expensive and ineffective. They argue that Mr Trump has manufactured the border emergency and that the wall has become a symbol of Trump’s anti-immigration platform.
BBC