A US appeals court has lifted a legal block on $3.6bn (£2.7bn) in defence funds, allowing President Donald Trump to spend the money on a US-Mexico wall.
The order by the 5th Circuit Court of Appeals overturned a lower court's ruling that stopped the funds being used while the case continues.
President Trump had directed the funds to be diverted from defence projects in February amid a budget debate.
Mr Trump's planned wall was the signature promise of his 2016 campaign.
White House press secretary Stephanie Grisham said in a statement that the lower court's ruling had been "illegitimate".
"This is a victory for the rule of law," she added.
Mr Trump announced his intention to use Pentagon funds for his border wall last February, after a 35-day government shutdown triggered by his demand that congressional Democrats approve funding for the barrier.
He declared a national emergency, arguing that Americans were in danger due to lax southern border security, using the measure to sidestep Congress and tap into defence funds.
The White House was then sued by the Texas border city of El Paso and the Border Network for Human Rights, an advocacy group, that argued there was no emergency requiring defence funds to be used.
"It's unfortunate that the people of El Paso will continue to suffer harm while the government appeals, but we're confident that we'll prevail again in this next stage of litigation," lawyers for the city said following the ruling.
No end in sight
President Trump has now won several legal battles that give him access to billions of dollars of military funds that he can use to build his border wall.
Having the money and spending it, however, are two very different things.
Even popular government construction projects take time - and there are still private property owners who will continue their court challenges to block new wall construction on their land.
As he prepares for his re-election campaign, the president can point to progress being made on one of his top 2016 promises, but it's been a long, grinding fight with no end in sight.