The Supreme Court cleared the way for the Trump administration to tap billions of dollars in Pentagon funds to build sections of a border wall with Mexico.

The court’s five conservative justices gave the administration the green light on Friday to begin work on four contracts it has awarded using Defense Department money. Funding for the projects had been frozen by lower courts while a lawsuit over the money proceeded. The court’s four liberal justices wouldn’t have allowed construction to start.

The justices’ decision to lift the freeze on the money allows President Donald Trump to make progress on a major 2016 campaign promise heading into his race for a second term. Trump tweeted after the announcement: “Wow! Big VICTORY on the Wall. The United States Supreme Court overturns lower court injunction, allows Southern Border Wall to proceed. Big WIN for Border Security and the Rule of Law!”

The Supreme Court’s action reverses the decision of a trial court, which initially froze the funds in May, and an appeals court, which kept that freeze in place earlier this month. The freeze had prevented the government from tapping approximately $2.5 billion in Defense Department money to replace existing sections of barrier in Arizona, California and New Mexico with more robust fencing.

The case the Supreme Court ruled in began after the 35-day partial government shutdown that started in December of last year. Trump ended the shutdown in February after Congress gave him approximately $1.4 billion in border wall funding. But the amount was far less than the $5.7 billion he was seeking, and Trump then declared a national emergency to take cash from other government accounts to use to construct sections of wall.

The money Trump identified includes $3.6 billion from military construction funds, $2.5 billion in Defense Department money and $600 million from the Treasury Department’s asset forfeiture fund.