The Supreme Court on Tuesday said the Biden administration must comply with a lower court’s ruling to reinstate President Donald Trump’s policy that required many asylum seekers to wait outside the United States for their cases to be decided.

The administration had asked the court to put on hold a federal judge’s order that the “Remain in Mexico” policy known as Migrant Protection Protocols (MPP) had to be immediately reimplemented. U.S. District Judge Matthew Kacsmaryk ruled earlier this month that the Biden administration did not provide an adequate reason for getting rid of the policy and that its procedures regarding asylum seekers who enter the country were unlawful.

Over the objections of the three liberal justices, the court’s conservative majority agreed that the administration had not done enough to justify changing the policy.

The administration “failed to show a likelihood of success on the claim that the memorandum rescinding the Migrant Protection Protocols was not arbitrary and capricious,” the court said in a short, unsigned order. In such emergency matters, the court often does not elaborate on its reasoning.

It said Justices Stephen G. Breyer, Sonia Sotomayor and Elena Kagan would have granted the administration’s request. The three also gave no reason.

The action could be an ominous sign for the new administration. The court is considering a request that it dissolve the pandemic-related evictions moratorium implemented by the Centers for Disease Control and Prevention, about which the court’s most conservative justices have already expressed skepticism.

The court often showed deference to the Trump administration in such emergency matters, including when the MPP was first implemented.

Acting solicitor general Brian H. Fletcher was explicit about that in his brief to the court.

“In recent years, this Court has repeatedly stayed broad lower court injunctions against Executive Branch policies addressing matters of immigration, foreign policy, and migration management,” Fletcher wrote. “It should do the same here.”

But in its order Tuesday night, the court cited a decision from 2020 in which it stopped the Trump administration from dismantling the Obama-era program Deferred Action for Childhood Arrivals, which protected undocumented immigrants who were brought into the country as children.

In that case, Chief Justice John G. Roberts Jr. sided with the court’s liberals in saying the Trump administration had failed to show that ending the program was not arbitrary and capricious.

“We do not decide whether DACA or its rescission are sound policies,” Roberts wrote in the 2020 decision. “The wisdom of those decisions is none of our concern. Here we address only whether the Administration complied with the procedural requirements in the law that insist on ‘a reasoned explanation for its action.’ ”

The difference is that decision was made after full briefing and argument, rather than on an emergency request to maintain the status quo while appeals continue.

Immigration rights groups denounced Tuesday’s Supreme Court order and urged the administration to continue its efforts to rescind the program rather than implement it.

“We are committed to doing everything we can to prevent this egregious policy from harming one more person and will use every tool at our disposal to oppose the Remain in Mexico policy, or any like it,” said Marielena Hincapié, executive director of the National Immigration Law Center. “We urge the Biden administration to do the same.”

It is unclear exactly what effect the ruling will have. The Department of Homeland Security said in a statement that it will continue to challenge the district court ruling. “As the appeal process continues, however, DHS will comply with the order in good faith,” the statement said. “Alongside interagency partners, DHS has begun to engage with the Government of Mexico in diplomatic discussions surrounding the Migrant Protection Protocols (MPP). DHS remains committed to building a safe, orderly, and humane immigration system that upholds our laws and values.”

In his brief to the court, Fletcher said reviving the program would be difficult. “MPP has been rescinded for 2.5 months, suspended for 8 months, and largely dormant for nearly 16 months,” Fletcher wrote.

“The district court’s mandate to abruptly reimpose and maintain that program under judicial supervision would prejudice the United States’ relations with vital regional partners, severely disrupt its operations at the southern border, and threaten to create a diplomatic and humanitarian crisis.”

A panel of the U.S. Court of Appeals for the 5th Circuit had largely sided with Kacsmaryk, refusing the government’s request to stay his ruling. It will expedite its consideration of the merits of the judge’s opinion, and the issue could return to the Supreme Court.

Shortly after taking office in January, President Biden said the administration would not continue enrolling migrants in the MPP and ordered a review of the program. He and immigration rights groups had criticized immigration policies implemented by the Trump administration as counterproductive and at odds with the nation’s historical practices.

“I’m not making new law. I’m eliminating bad policy,” Biden said at the time.

Under the program, more than 60,000 asylum seekers were sent to wait outside U.S. territory while their claims were processed in U.S. immigration courts. The states of Texas and Missouri filed suit against the Biden administration, saying that rescinding the Trump policy would result in a flow of undocumented immigrants into those states.

In their brief to the court, the states’ attorneys general said revoking the MPP “amplified the ongoing border crisis into an outright disaster, emboldening criminal cartels and human traffickers who prey on vulnerable migrants.”

While the litigation was underway, Homeland Security Secretary Alejandro Mayorkas filed a seven-page memorandum on June 1 detailing what he saw as the MPP’s shortcomings and stating why his department was rescinding the policy adopted in late 2018.

On Aug. 13, Kacsmaryk, a Trump-nominee who took the bench in 2019, ruled for the states. He vacated Mayorkas’s decision and issued a nationwide permanent injunction, to take effect in seven days. He required the Department of Homeland Security to “enforce and implement MPP in good faith” until Mayorkas provided additional explanation for his decision and until the department has “sufficient detention capacity to detain all aliens” arriving at the border without authority to enter.

Kacsmaryk said the law gave the administration only two options for migrants seeking asylum: “mandatory detention or a return to a contiguous territory.”

At the Supreme Court, the Biden administration said that was an “egregious” misreading of the law. The law gives the executive branch discretion, the administration argued, and said such a reading of the law “has never been accepted by any presidential administration since the statute’s enactment in 1996, including while MPP was operational.”

It defended Mayorkas’s decision-making but said that even if it was insufficient, the solution would be to require additional reasoning, not to reimplement a program that requires delicate negotiations with Mexican officials and others.

While Biden pledged during the campaign to end the Trump-era program, he has continued the prior administration’s policy of expelling migrants from the southern border on the grounds of preventing further spread of the coronavirus.

Thousands of single adult migrants are still being expelled, although in recent months, the Biden administration has admitted most migrant families and unaccompanied minors to seek refuge in the United States.

Omar Jadwat, director of the Immigrants’ Rights Project at the American Civil Liberties Union, said the Biden administration “must take all steps available to fully end this illegal program, including by re-terminating it with a fuller explanation.”

The case is Biden v. Texas.

Nick Miroff and Maria Sacchetti contributed to this report.