A federal appeals court ruled Thursday that the Trump administration's policy barring migrants from seeking asylum at the U.S.-Mexico border is unlawful, delivering a major legal blow to one of the administration's central immigration enforcement tools. The court found the ban conflicts with existing federal law, which grants individuals the right to apply for asylum regardless of how or where they enter the country.

The ruling puts in jeopardy a key pillar of the administration's effort to dramatically reduce the number of migrants processed at the southern border. Administration officials have defended the policy as a necessary measure to manage what they describe as an ongoing crisis at the border, arguing the executive branch has broad authority to restrict entry during periods of high migration.

The case now raises questions about how the administration will respond, whether by appealing to the Supreme Court or seeking alternative legal mechanisms to enforce restrictions at ports of entry and between them. Legal experts noted the decision reaffirms longstanding statutory protections for asylum seekers enshrined in the Immigration and Nationality Act.

Immigrant advocacy groups praised the ruling as a vindication of domestic and international legal obligations the United States has undertaken to protect those fleeing persecution. Critics of the ban had argued from the outset that the administration was attempting to circumvent congressional authority over immigration law through executive action.

The decision adds to a growing body of court rulings that have constrained aspects of the administration's immigration agenda. Officials have previously faced judicial blocks on other enforcement measures, though some have been reinstated on appeal or modified in response to court orders.