WASHINGTON, June 13 — US immigrant rights groups sued the Biden administration yesterday over a new policy that bars most migrants caught crossing the US-Mexico border illegally from claiming asylum.

The groups, led by the American Civil Liberties Union, argued restrictions implemented last week violated US asylum law and that Biden failed to follow proper regulatory procedure. The lawsuit was filed in federal court in Washington, DC.

Biden, a Democrat seeking another term in November 5 elections, has grappled with millions of people caught illegally crossing the southwest border during his presidency. Immigration is a top election issue and Biden’s Republican challenger, former President Donald Trump, has vowed to crack down aggressively if he wins another term in the White House.

Biden has toughened his stance in recent months, backing a bipartisan Senate bill that would surge resources to the border and expand enforcement capacity. The new ban mirrors Trump-era policies that sought to deny migrants access to asylum at the border and utilises the same legal authority as Trump’s travel bans blocking people from majority-Muslim nations and elsewhere.

Lee Gelernt, deputy director of the ACLU’s Immigrants’ Rights Project, said the Biden administration "lacks unilateral authority” to override laws created by Congress, citing previous legal decisions related to Trump-era policies.

Migrants caught crossing illegally can be quickly deported or turned back to Mexico under the Biden measure. The ban included exceptions for unaccompanied children, people who face serious medical or safety threats and victims of trafficking.

Key operational questions remain unclear, including how the US would quickly deport migrants from countries that are far away or have frosty relations with the US and whether Mexico will accept more non-Mexico migrants apprehended by US authorities.

The number of migrants caught illegally crossing the border dropped by 20 per cent late last week, which one senior US border official said signalled "possible early success” deterring illegal immigration.

White House spokesperson Angelo Fernandez Hernandez defended the asylum ban, saying it was necessary because "border encounters remain too high” and Republican lawmakers have blocked Biden-backed legislation.

In the lawsuit filed on Wednesday, the immigrant rights groups also targeted a part of the Biden asylum ban that requires migrants to express a fear being returned to their home countries before being able to seek humanitarian protection rather than have US authorities ask about it.

The groups said people who recently crossed the border "may be hungry, exhausted, ill, or traumatised after fleeing persecution in their home countries and danger in Mexico.” — Reuters