“We want to cross but we can’t,” said Patricia Castañeda, 34, from Honduras, as she sat in front of her makeshift home in Matamoros in a red tent covered with black sheets of plastic. “You can only apply through CBP One,” she said, referring to the mobile app created by the U.S. government to encourage migrants to seek lawful entry.

Biden administration officials for months predicted a migration surge after May 11, the date set by the White House for the pandemic measures known as Title 42 to lift. That did not occur, at least initially, giving U.S. authorities a minor respite after record numbers of illegal crossings this week.

Interviews with migrants waiting on the Mexican side suggested that the U.S. threats to ramp up deportations starting Friday spurred many to cross before — not after — Title 42’s expiration. Unlawful crossings topped 10,000 per day this week, the highest levels ever.

A Mexican border guard standing near Castañeda said illegal crossings had abruptly halted. “Title 42 ended — now it’s over,” he said, declining to give his name because he was not authorized to talk to reporters. “Today they know they’ll be deported. Yesterday they were sent back to Mexico. Now they can be sent back to their countries.”

The Title 42 pandemic policy, which began during the Trump administration, was used by U.S. authorities to quickly expel more than 2.6 million migrants back to Mexico or their home countries over the past three years. But the expulsions carried no legal consequences, prompting many to make repeat entry attempts.

The Biden administration says the new measures it implemented Friday will make it easier for authorities to deport asylum seekers who cross illegally, while expanding opportunities for migrants to reach the United States through lawful channels including the CBP One app.

The pent-up frustration of many who risked everything to reach the U.S. border — spending their savings to pay “coyotes,” or smugglers, for journeys of thousands of miles, trekking through dangerous jungles — made it clear that the problem was far from over. Elsewhere in Matamoros, hundreds of migrants, mostly from Mexico and Haiti, lined up at the official border crossing into Brownsville on Friday afternoon to seek asylum.

U.S. border guards said Friday’s line was longer than usual because of people seeking asylum after the end of Title 42.

Several Haitians said they had gotten appointments via the CBP One app. But many Mexicans in the line said they just showed up, hoping that now they wouldn’t be turned back.

Among them was Ricardo Vasquez, 30, who stood in the long passageway with his 9-year-old daughter, Miley, and 11-year old son, Jesus Gael. The children wore plastic rosaries around their necks.

“We are going to hand in our papers. To show credible fear, or something like that,” said Vasquez. He said he was fleeing Acapulco, where rival drug gangs have been battling for control. He said a Mexican friend had told him that the end of Title 42 would open the door to cases like his.

Any decline in the number of migrants attempting to enter illegally could help ease capacity strains at border stations and processing centers. Nearly 30,000 migrants were in Customs and Border Protection custody at one point this week, triple the official capacity. Eight of nine Border Patrol sectors said their holding cells were stretched beyond their limits.

Shortly before the Title 42 policy lifted at the end of Thursday, a federal judge in Florida temporarily blocked the Biden administration from releasing migrants without a court date as a way to alleviate overcrowding.

U.S. District Judge T. Kent Wetherell II wrote in his ruling that the border had been “out of control” for two years and that the president and Congress had failed to fix it. He said he would not condone a new emergency policy that Border Patrol Chief Raul Ortiz issued this week allowing for the release of some vetted migrants into the United States, since it was similar to a policy he had rejected as unlawful in March.

The Biden administration had warned the judge, a Trump appointee, that border facilities could become dangerously overcrowded if he blocked the emergency releases, but Wetherell wrote that the administration’s “doomsday rhetoric rings hollow.”

Blas Nuñez-Neto, the top border and immigration policy official at the Department of Homeland Security, told reporters during a briefing Friday that the administration would comply with the court order, but he called the ruling harmful.

The judge’s order, he said, “will result in unsafe overcrowding at CBP facilities and undercut our ability to efficiently process and remove migrants, which will risk creating dangerous conditions for Border Patrol agents as well as noncitizens in our custody.”

Advocates for immigrants also challenged the Biden administration’s policies late Thursday in U.S. District Court for the Northern District of California, arguing that the new asylum restrictions that took effect Friday mimic Trump-era initiatives blocked by federal courts.

The Biden administration has rejected comparisons to the last administration, emphasizing that it is expanding safe, legal pathways for migrants while attempting to deter them from hiring smugglers.

The advocacy groups argued that federal law allows migrants to seek asylum, whether they entered legally or not. They also criticized the Biden administration’s assumption that anyone who traveled through another country should have sought refuge there, noting that many nations lack robust asylum systems.

“The Biden administration’s new ban places vulnerable asylum seekers in grave danger and violates U.S. asylum laws. We’ve been down this road before with Trump,” Katrina Eiland, managing attorney with the ACLU Immigrants’ Rights Project, said in a statement. “The asylum bans were cruel and illegal then, and nothing has changed now.”

The Biden administration’s legal pathways face a separate federal court challenge in Texas. Republican officials there and in other states sued in January to stop a special program that allows people from Cuba, Venezuela, Haiti and Nicaragua to apply for “parole” to enter the United States legally on a provisional status for two years, to discourage them from crossing the border. Migrants from those four nations have been arriving at the southern border in large numbers and are difficult to manage because the United States cannot easily deport them to their home countries.

In El Paso, where thousands of migrants have attempted to enter the United States in recent days, Title 42 ended quietly as well. Nearly all of the migrants who had gathered between the Rio Grande and the U.S. border wall were gone, moved out steadily by U.S. buses and vans.

There were no longer crowds outside the border wall gates marked 40 and 42 — some of the most active sites of migrant crossings recently. About a dozen migrants were camped on the opposite side of the border wall, but entry to the gates was blocked with thickets of concertina wire.

Some migrants who had been released in downtown El Paso said they were relieved to have made it through.

“I was eager to cross when Title 42 was still active because I do not want to be deported,” said Luis Colmonare, a 41-year-old Venezuelan who stood with a U.S. government folder firmly in his hand.

Colmonare said he crawled through a little door that was cut into the border wall Thursday. “They apprehended me,” he said, placing his hands together to simulate being handcuffed.

“Thankfully everything turned out well,” he said. His court hearing is in July.

Many of the migrants in Matamoros who hadn’t crossed before Title 42 lifted said they were unsure what they would do next. The flow of new arrivals didn’t let up.

Genesis Cardenas, 30, sat on a curb near the tightly guarded international bridge early Friday, holding her squirming 10-month-old daughter, Susej Paredes, whose name spells “Jesus” backward. The Venezuelan woman and her husband left Peru on April 18, hoping to reach the U.S. border before the Title 42 policy expired. But they got delayed and arrived by bus Friday morning from Mexico City.

Her group of 15 friends and relatives split up as they encountered problems along the journey — including lack of money.

Her husband, Anthony Paredes, 29, sitting alongside her, said he had worked in Peru delivering food by motorcycle and doing construction and gardening work. He said he and his wife struggled. “We wanted to seek new opportunities.”

The family seemed at a loss. “Look,” said Genesis, pulling back the baby’s diaper to reveal an ugly red rash. They were nearly out of money. “We are asking people, can we give ourselves up” to immigration officials?, she said.

Ramon Elias Suarez, 53, was also at a loss. He’s been in Matamoros for three months, living in the tent camp. He’s tried repeatedly to access the CBP One app, showing a reporter how he’d get a reply that the app needed to be updated. When he pressed the button to do so, it took him to a Google symbol.

“I’m going to continue to fight for an appointment,” he said. “Maybe I’ll go to the bridge and explain my case.”

Sheridan reported from Matamoros, Mexico, Mata from El Paso, and Sacchetti and Miroff from Washington.