The Biden administration has announced its most restrictive border control measures to date, as it tries to get out ahead of an expected surge in migration when a pandemic-era expulsion policy lifts in May.

Under the new rule, asylum seekers who attempt to enter the U.S. illegally – or without first seeking protection in the countries they transit – will be barred from entering the U.S.

Pro-migration groups say the rule is “ludicrous and life-threatening” – and defies decades of asylum policy enshrined in U.S law.