The US Court of Appeals for the Fifth Circuit Monday denied the Biden administration’s appeal to terminate the Trump-era Migration Protection Protocols (MPP), affirming a Texas district court’s decision that would require the administration to leave the MPP intact.

The MPP, also known as the “Remain in Mexico” policy, requires asylum-seekers on the southern border to wait in Mexico, sometimes for years, while their asylum claims are processed in the US immigration system. The policy has received criticism for violating international law that forbids states from turning away legitimate asylum seekers. However, Trump-era supporters advocated for the policy as being necessary to address large numbers of migrants arriving from Mexico.

Following the Biden administration’s decision to end MPP in early 2021, Texas and Missouri filed suit in federal court. They argued that an abrupt cancellation of MPP was arbitrary and capricious and that border states would be burdened by asylum seekers. Following a district court order requiring MPP to be reinstated, the Biden administration appealed.

The appeals court agreed with the plaintiffs’ assertion, as well as the district court’s finding, that the Biden administration’s cancellation of MPP violated the Administrative Procedure Act as well as 8 U.S.C. § 1225, an immigration statute that governs the removal of noncitizens filing claims for asylum and permits the return of asylum-seekers to contiguous nations pending proceedings.

Furthermore, the court disagreed with the administration’s claim that the dispute had been rendered moot through the Department of Homeland Security’s issuance of additional memoranda on October 29 that clarified the decision to terminate MPP. The court found that mootness only occurs once a controversy between parties is dead and gone, and that “the controversy between these parties is very much not dead and gone.” Furthermore, the court was unsatisfied with the government’s claim that issuing a new memo cured problems with the old memo, stating that it risked “supplant[ing] the rule of law with the rule of say-so.”

Under this ruling, the federal government must resume MPP proceedings in Mexico. It is unclear if the Biden administration will pursue further litigation to end MPP. The US Supreme Court denied the administration’s request stay of the district court’s order in August, finding it likely that the MPP cancellation was arbitrary and capricious.