EL PASO, Texas (NewsNation) — The Texas National Guard deployed members on the bank of the Rio Grande, which became a popular crossing point for migrants, and used razor wire to cordon off a gap in the border fence in an attempt to turn back migrants from the U.S. They’re also using a loudspeaker to announce in Spanish that it’s illegal to cross there.

The Texas Military Department said the deployment is part of Gov. Greg Abbott’s “enhanced border security effort” and will include a Security Response Force comprised of “elements” from the 606th Military Police Battalion “trained in civil disturbance operations and mass migration response.”

This comes as Title 42, the pandemic-era limits on border crossings, was slated to expire Wednesday — and the federal government opposed an effort by some conservative-leaning states to keep them in place. But hours before they were about to lift, the Biden administration asked the Supreme Court not to remove them before Christmas.

Just after midnight, all was quiet on the banks of the Rio Grande in El Paso where the Texas National Guard was posted — though thousands of people have filled shelters and otherwise sought refuge along the border while the legal wrangling unfolds. Hundreds of migrants initially gathered by the concertina wire put up by the guard but left after being told by U.S. officials to go to a gate to be processed in small groups.

First Sgt. Suzanne Ringle said one woman went into labor in the crowd on the riverbank and was assisted by Border Patrol agents. She added many children were among the crowd.

Texas said it was sending 400 National Guard personnel to the border city after local officials declared a state of emergency. El Paso Mayor Oscar Leeser said the declaration was aimed largely at protecting vulnerable migrants, while a statement from the Texas National Guard said the deployment included forces used to “repel and turn back illegal immigrants.”

“The military presence is a bit excessive, but you have to respect it because it’s another country’s border,” said Ciudad Juarez, Mexico Mayor Cruz Pérez Cuéllar.

For thousands of migrants, the Rio Grande is the final leg of a treacherous journey. The crossings happen daily in El Paso.

“We’ve been crossing one border at a time. We went to Piedras Negras to Turion, and then took a train here,” said Renato Ortiz, a migrant.

An average of 7,500 migrants cross the US-Mexico border daily. The Department of Homeland Security estimates that number could potentially more than double once Title 42 is lifted.

El Paso Mayor Oscar Leeser said for his city alone, that could mean more than 150,000 migrant crossings per month.

“I really believe that today our asylum seekers are not safe, as we have hundreds and hundreds on the streets, and that’s not the way we want to treat people,” Leeser said.

Leeser warned that shelters across the border in Juarez were packed to capacity, with an estimated 20,000 migrants prepared to cross into the order.

That’s forced many migrants to sleep through 30-degree winter temperatures with nothing but blankets in makeshift camps on the streets.

Jhorman Morey, a 38-year-old mechanic from Venezuela, said he was waiting for a decision on asylum restrictions before attempting to cross into the U.S. He warmed his hands by a campfire with a half-dozen other Venezuelan migrants on the Mexican side of the Rio Grande, as other migrants waded through shallow waters toward a gate in the U.S. border fence.

“I want them to decide” on the public health rule known as Title 42, said Morey, who arrived in the Mexican city of Juarez, across the border from El Paso, six weeks ago. He now rarely eats after exhausting his savings.

The city has rushed to expand its ability to accommodate more migrants by converting large buildings into shelters, as the Red Cross brings in 10,000 cots.

“We will continue to be prepared for whatever is coming through,” Leeser said.

Some who have booked passage are permitted to shelter inside the airport.

Under the restrictions, officials have expelled asylum-seekers inside the United States 2.5 million times and turned away most people who requested asylum at the border, on grounds of preventing the spread of COVID-19 under Title 42.

Immigration advocates have said that the restrictions go against American and international obligations to people fleeing to the U.S. to escape persecution, and that the pretext is outdated as coronavirus treatments improve. They sued to end the use of Title 42; a federal judge sided with them in November and set the Dec. 21 deadline.

Conservative-leaning states appealed to the Supreme Court, warning that an increase in migration would take a toll on public services and cause an “unprecedented calamity” that they said the federal government had no plan to deal with.

Though the Wednesday expiration date had been set weeks ago, the U.S. government asked for more time to prepare — while saying that it has sent more resources to the border and maintaining that the solution is not to extend the rule indefinitely.

The Associated Press contributed to this report.