A US federal judge has blocked President Joe Biden's new regulation restricting asylum access at the US-Mexico border. The regulation, which took effect when Covid-era Title 42 restrictions ended in May, presumed most migrants are ineligible for asylum if they passed through other nations without seeking protection elsewhere first or failed to use legal pathways for US entry.

The judge's ruling came after a legal challenge from the American Civil Liberties Union (ACLU) and other groups who argued that the regulation violated US law and put migrants at serious risk.

The Biden administration has appealed the ruling to the US 9th Circuit Court of Appeals. While the ruling is a temporary victory for rights groups, it will have little immediate effect at the border as the judge has stayed the decision for two weeks pending the appeal.

The Biden administration has argued that the regulation is necessary to deter migration and has pointed to new programs and lawful immigration pathways as alternatives for migrants.

However, critics argue that these options are not viable for most migrants and that the regulation violates international law. The ruling comes as the number of migrants caught crossing the border illegally has plummeted in recent months. Whether this trend will continue if the new asylum restrictions are blocked remains uncertain.