WASHINGTON - The U.S. Supreme Court agreed on Monday to hear a defense by President Donald Trump's administration of the government's authority to limit the processing of asylum claims at ports of entry along the U.S.-Mexico border.

The court took up the administration's appeal of a lower court's determination that the "metering" policy, under which U.S. immigration officials could stop asylum seekers at the border and decline to process their claims, violated federal law. The policy was rescinded by former President Joe Biden, but Trump's administration has indicated it would consider resuming it.

The Supreme Court is expected to hear the case and issue a ruling by the end of June.

The metering policy is separate from the sweeping ban on asylum at the U.S.-Mexico border that Trump issued after returning to the presidency on January 20. That policy faces an ongoing legal challenge.

Under U.S. law, a migrant who "arrives in the United States" may apply for asylum and must be inspected by a federal immigration official. The legal issue in the case is whether asylum seekers who are stopped on the Mexican side of the U.S.-Mexico border have arrived in the United States.

U.S. immigration officials began turning away asylum seekers at the border in 2016 under Democratic former President Barack Obama amid a migrant surge. The metering policy was formalized in 2018 during the Republican Trump's first term in office, with border officials being permitted to decline processing asylum claims when ports of entry were at capacity. Biden, a Democrat, rescinded the policy in 2021.

The advocacy group Al Otro Lado launched the long-running legal challenge in 2017 with a lawsuit arguing that the metering policy violated federal law, which states that any non-U.S. citizen who arrives in the United States may apply for asylum.    

Trump's Justice Department argued in a Supreme Court filing that the case is not moot and that his administration likely would resume the use of metering "as soon as changed border conditions warranted that step," without providing specifics.