(NewsNation) — Texas Gov. Greg Abbott on Monday signed legislation that gives law enforcement officials the power to arrest migrants who enter the state illegally from Mexico.

The bill, Senate Bill 4, gives local judges authority to order them to leave the country, testing the limits of how far a state can go to enforce immigration laws.

“These laws will help stop the tidal wave of illegal entry into Texas,” Abbott said in his statement.

The law, which takes effect in March, grants any Texas law enforcement, including school resource officers, the power to arrest people who are suspected of entering the country illegally. Once in custody, they could either agree to a Texas judge’s order to leave the U.S. or be prosecuted on misdemeanor charges of illegal entry. Migrants who don’t leave could face arrest again under more serious felony charges.

Abbott, who signed the law in front of a section of border fence in Brownsville, predicted the number of people crossing illegally into Texas would drop by “well over 50%, maybe 75%.” He did not offer evidence for that estimate.

“The consequences of it are so extreme that the people being smuggled by the cartels, they will not want to be coming into the state of Texas,” Abbott said during the signing.

Abbott has continued to push the limits Texas can take to stop illegal immigration, including placing razor wire at certain locations and installing a chain of orange buoys along the banks of the Rio Grande, which have snagged and injured some asylum-seekers. which have created legal battles with the Biden administration.

SB 4 adds another tension point over immigration amid a struggle between the White House and Senate negotiators to reach a deal on border security. Republicans in Congress are demanding changes to the immigration system in exchange for any help for Ukraine, Israel and other national security needs.

Texas Republicans have increasingly challenged the U.S. government’s authority over immigration, saying President Joe Biden’s administration isn’t doing enough to control the 1,950-mile southern border. Texas has bused more than 65,000 migrants to cities across America since August 2022.

On Monday, the U.S. Customs and Border Protection suspended international railway crossing in El Paso and Eagle Pass for the first time to redirect agents to assist in processing migrants.

Troy Miller, CBP’s acting commissioner, said the closures at Eagle Pass and El Paso were a response to more migrants traveling on freight trains, particularly over the last week.

Miller said authorities are seeing “unprecedented” arrivals at the border, topping 10,000 crossings on some days this month.

Shortly after Abbott signed the new law, the American Civil Liberties Union of Texas said it would challenge the measure in court. More than 20 congressional Democrats also signed a letter urging the U.S. Justice Department to sue to stop the SB 4.

“SB 4 is dangerous for the people of Texas and interferes with the federal government’s exclusive authority over immigration and foreign affairs,” the letter read.

Mexico’s government also has rebuked the measure. Under bilateral and international agreements, Mexico is required to accept deportations of its own citizens, but not those of other countries. Under the Texas law, migrants ordered to leave would be sent to ports of entry along the border with Mexico, even if they are not Mexican citizens. In September and October, Venezuelans were the largest nationality arrested for illegally crossing the U.S. border.

Opponents have called SB 4 the most dramatic attempt by a state to police immigration since a 2010 Arizona law — denounced by critics as the “Show Me Your Papers” bill — that was largely struck down by the U.S. Supreme Court.