After passing a policy requiring asylum seekers to wait in Mexico until their cases can be heard, the administration has erected the tent complexes so immigration judges in San Antonio can hold hearings remotely.

The acting heads of the nation’s immigration agencies arrived here Tuesday to visit a makeshift courthouse, built from tents and shipping containers, where the administration will apply the experimental and legally tenuous border policy called Migration Protection Protocols, also known as “remain in Mexico.”

The visit underscored the improvisational enforcement approach that Homeland Security officials have taken to drive down border crossings in the absence of a bipartisan immigration overhaul in Washington. The administration has budgeted up to $155 million to operate five temporary MPP courts along the length of the border, with the overarching goal of replacing the asylum processing model that President Donald Trump has disparaged as “catch and release.”

By routing migrants directly from official border crossings into the adjacent court complex, U.S. authorities can fulfill the obligation to give asylum seekers access to the U.S. court system without giving them physical access to the United States. So far this year, at least 42,000 migrants have been sent back to Mexico under the MPP program, and a growing number have opted to return to Central America instead of waiting.

The acting Homeland Security officials who visited the Laredo courts Tuesday defended them as a lawful and appropriate response to a border crisis that has pushed illegal crossings this year to their highest levels in more than a decade. Acting Homeland Security Secretary Kevin McAleenan said the tent complex will allow for a more “expeditious process” to handle the surge in asylum claims that have overwhelmed the U.S. asylum system.

“We are bringing more integrity to the system,” McAleenan said. “This will deter people who don’t have valid asylum claims and allow us to get to those who do have valid claims more quickly.”

Federal judges have allowed the government to continue sending asylum seekers back to Mexico under MPP until the legality of the policy is determined in court, perhaps as soon as next month. The Supreme Court ruled last week that Homeland Security officials can also go forward with a new rule that bars asylum seekers who fail to seek protection in another country while traveling to the United States.

Both policies, if fully implemented, would place nearly insurmountable legal barriers on the Central American migrant families who have arrived in record numbers bearing stories of gang threats and police corruption. The majority of their claims do not meet the requirements for U.S. asylum, however, and Homeland Security officials say too many migrants are attempting to game the system to gain easy entry.

McAleenan said the MPP court model will give applicants the ability to wait in a “nondetained setting” while their claims are processed. But they will have to wait in Mexico — many of them in Nuevo Laredo, one of the most fearsome places for migrants along the length of the border.

McAleenan was joined Tuesday by Matt Albence, acting Immigration and Customs Enforcement director; Mark Morgan, acting Customs and Border Protection commissioner; and Ken Cuccinelli, acting director of U.S. Citizenship and Immigration Services.

None of the men has been formally nominated to hold his job on a more permanent basis by Trump, who has said he prefers keeping his top officials on a short leash, giving him more flexibility to fire them.

Two MPP courts have opened this month in South Texas, one here in Laredo and another in Brownsville, where migrants who have been arrested and returned to Mexico can arrive at a U.S. border crossing on the day of their appointment. The 50,000-square-foot Laredo facility can handle about 400 migrants per day, authorities said.

Instead of hearing their claims and releasing them to await a decision at a bricks-and-mortar courthouse, the tent complex funnels applicants through a series of air-conditioned tents, trailers and containers repurposed as waiting rooms and video-conference chambers, allowing judges in San Antonio to conduct hearings remotely.

Immigrant legal advocates say the temporary court facility drastically limits their ability to counsel asylum seekers and inform them of their rights. Homeland Security officials say the tent complex is a “detained” setting and requires higher levels of security.

A record number of migrant families, mostly from Central America, have crossed into the United States during the past 18 months, but border arrests have fallen by more than 56% in the past three months as U.S. agents have sent more migrants to wait outside U.S. territory, and the Mexican government carries out a broad crackdown under pressure from Trump.

A few dozen migrants have passed through the improvised courthouse each day so far. Those scheduled for 8:30 a.m. hearings are instructed to arrive at 4:30 a.m. on the Mexican side of the border crossing, an appointment that requires them to navigate Nuevo Laredo’s dangerous streets in the middle of the night.

Those who express a fear of harm in Mexico can also appeal the order to be sent back across, but very few applicants have been allowed to stay on the U.S. side of the border and avoid being turned back to Mexico.

Morgan, the acting CBP commissioner, said it was Mexico’s responsibility to provide security for migrants en route to their court hearings on the U.S. side. “Mexico is equally responsible for their care when they cross over,” Morgan said.

“We have to be very, very careful, as our own sovereign nation, to paint an entire nation as a war zone,” he said, doubting the accounts of kidnappings and disappearances of migrants at the hands of criminal cartels. “I don’t believe that. We are not receiving that information from the government of Mexico.”

U.S. officials said they would be willing to schedule hearings later in the day if Mexico would allow returnees to be sent back to Mexico later than the current deadline of 4 p.m.

The court complex has a larger courtroom facility as well as smaller private rooms fashioned from shipping containers where migrants will have the chance to recount their stories of persecution, abuse or desperate escape to immigration judges viewing them on computer monitors.'

The shift toward a large number of family groups was evident in a smaller waiting room among the tents designed for children, with brand-new changing tables for babies and toddler-sized bookshelves with titles in English including “Pig the Pug,” “Time for Bed” and “Playtime Peekaboo.”