Texas authorities have arrested nearly 10,000 migrants who illegally crossed the U.S.-Mexico border under a new "arrest and jail" operation aimed at deterring illegal immigration.

Following the successful arrests, Texas passed a new law that will bolster the smaller-scale operation to expand the authority to make arrests, as well as give local judges the authority to order the migrants out of the country. The changes go into effect in March.

The new law comes after Texas first launched the smaller-scale operation to arrest migrants on misdemeanor trespassing charges in July 2021 as Texas-Mexico border crossings reached 1.2 million that fiscal year.

The initiative allows border landowners to enter agreements with the state authorizing trespassing arrests, clearing the way for law enforcement to apprehend migrants who enter the U.S. through those properties.

TEXAS GOV. ABBOTT SIGNS BILL MAKING ILLEGAL IMMIGRATION A STATE CRIME

A large group of migrants walking

Migrants take part in a caravan toward the border with the United States in Tapachula, Chiapas State, Mexico, on Dec. 24. (STR/AFP via Getty Images)

Republican Gov. Greg Abbott had predicted the trespassing arrests would produce swift results.

"When people start learning about this, they’re going to stop coming across the Texas border," Abbott told Fox News in July 2021.

Border crossings topped 1.5 million over the past fiscal year.

"They’re still coming through here," Maverick County Sheriff Tom Schmerber said.

MIGRANT CRISIS INCREASING STRAIN ON BORDER OFFICIALS, IMMIGRATION COURTS WITH MASSIVE NUMBERS

Migrants crossing the border

People camp as they wait to cross the border between Mexico and the United States in Ciudad Juarez, Mexico on December 27, 2023.  (Christian Torres/Anadolu via Getty Images)

The trespassing arrests are spearheaded by the Texas Department of Public Safety, which said the state's border operation has resulted in more than 37,000 total criminal arrests.

Spokesperson Ericka Miller said those arrested included gang members, human traffickers, sex offenders and others.

NOVEMBER SAW NEARLY QUARTER OF A MILLION MIGRANT ENCOUNTERS AMID NEW BORDER SURGE

"Had we not been there, all of it likely would have crossed into the country unimpeded," Miller told The Associated Press. "The state of Texas is working to send a message to those considering crossing into the country illegally to think again."

Migrants walking in water

Immigrants walk along the fortified bank of the Rio Grande after crossing the border from Mexico into the United States as Border Patrol agents look on in Eagle Pass, Texas. (John Moore/Getty Images)

The trespassing arrests have been a cornerstone of Abbott’s nearly $10 billion border mission known as Operation Lone Star that has tested the federal government’s authority over immigration.

CLICK HERE TO GET THE FOX NEWS APP

In addition, Abbott has sent an estimated 80,000 migrants on buses to Democrat-led cities, including New York, Chicago, and Washington, D.C.

Mexican President Andrés Manuel López Obrador said on Friday that his government was aware of a new migrant caravan and said it would step up efforts to contain immigration.

Migrants, border official near the border wall

Migrants who crossed the border through the Rio Bravo from Mexico into the U.S. wait next to the U.S. border wall where Border Patrol agents stand guard in Ciudad Juárez, Mexico.  (Getty Images)

The arrests have drawn legal challenges, including claims of due process violations. Civil rights organizations have also sued to stop the new law signed by Abbott from taking effect, calling it an unconstitutional overreach that encroaches on the U.S. government's immigration authority.

The Associated Press contributed to this report.