WASHINGTON (AP) — A federal judge has rejected a request from the Trump administration to toss a lawsuit challenging the detention of migrants at the U.S. Navy base at Guantanamo Bay.

In a ruling Friday, U.S. District Court Judge Sparkle L. Sooknanan denied the federal government’s motion to dismiss the case and has set a hearing for next week for the parties to discuss next steps in this case.

President Donald Trump in January announced his administration would use a detention center at Guantanamo to hold tens of thousands of the “worst criminal aliens,” as part of his wider immigration crackdown.

Between February and June, the federal government held around 500 immigrants at Guantanamo, according to Sooknanan, as authorities used the base as a way station for immigrants with final removal orders.

American Civil Liberties Union attorney Lee Gelernt, who argued the case, said in a statement Saturday that he hopes the ruling “will put an end to the Trump administration’s unlawful policy of sending immigrants to military bases in the middle of nowhere solely for the theatric value.”

The ACLU and other advocacy groups have argued that transporting immigrants to Guantanamo is unlawful. The Trump administration has said it has broad authority to hold immigrants with final deportation orders at the facility.

In a statement, Tricia McLaughlin, an assistant secretary at the Department of Homeland Security, said, “We look forward to a higher court’s vindication of our use of this facility to keep criminals off American streets.”

The base, often referred to as “Gitmo,” is best known for the suspects brought there after the Sept. 11, 2001, attacks.