Austin, Texas - Texas Governor Greg Abbott signed a hugely controversial bill on Monday that would allow state police to arrest and deport migrants who illegally cross into the US from Mexico.

The move by far-right Republican sets up a potential legal clash with the federal government, which generally sets and enforces immigration laws.

Abbott, speaking at a live-streamed signing ceremony in Brownsville on the US-Mexico border, accused President Joe Biden of doing "nothing to halt illegal immigration."

"Joe Biden's deliberate inaction has decimated America," Abbott said.

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The governor claimed that some eight million people have crossed the border illegally since Biden took office in January 2021, and defended the new law as constitutional, saying Texas had been left to "fend for itself."

He said the bill passed by the Republican-majority Texas state legislature last month was needed to "stop the tidal wave of illegal entry into Texas."

Abbott explained the bill, known as SB4, makes it a "criminal offense for illegal entry into Texas from a foreign nation."

"For repeat offenders it creates the offense of illegal reentry with a potential prison sentence term of up to 20 years," he said, adding that the legislation "provides a mechanism to order an illegal immigrant to return to the foreign nation from which they entered."

The law, which is expected to be challenged in court by the Biden administration and civil liberties groups, is to go into force in March and is the latest flashpoint between the Republican governor and the federal authorities.

The Justice Department has filed a lawsuit seeking the removal of a floating barrier installed by Texas authorities in the Rio Grande River to stop migrants crossing from Mexico.

Donald Trump, the frontrunner for the 2024 Republican presidential nomination, has made immigration a centerpiece of his White House campaign and criticized Biden's policies during a recent visit to the US-Mexico border.

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Trump and Abbott, who has endorsed the former president's White House bid, blame Biden for what they insist is a crisis and have ratcheted up extreme anti-immigrant rhetoric.

This comes as borderlands residents are already experiencing militarization of their communities, incessant ID checks often motivated by racial profiling, and increased coordination among law enforcement agencies.