Texas Republican Gov. Greg Abbott signed a controversial law on Monday that criminalizes illegal entry into the southern US state, which borders Mexico, something that is normally the sole discretion of federal authorities.

The avowed supporter of Donald Trump, who accuses Democratic President Joe Biden’s administration of “deliberate inaction” on illegal immigration, symbolically signed the law in Brownsville in front of a section of the wall on the border with Mexico — his signature project Republican ex-president.

The law makes it a “criminal offense to enter Texas illegally from a foreign country” and is punishable by up to 20 years in prison in the event of a repeat offense, Governor Abbott said.

The text, which is supposed to go into effect in March, gives state authorities the power to arrest migrants and deport them to Mexico — also formally a federal authority — which foreshadows legal challenges that will challenge whether the law is constitutional.

The Mexican government reacted on November 15 to the passage of the disputed law by “categorically rejecting any measure” that “gives local authorities or any state the ability to repatriate Mexican citizens or foreigners to Mexico,” according to a statement from the foreign ministry.

Mr. Trump, campaigning to return to the White House, accuses — like Mr. Abbott — President Biden and his administration of turning a blind eye to illegal immigration on the US southern border. Most of the migrants are citizens of Latin American countries, who leave their homelands to escape poverty and violence.