A federal appeals court said on Thursday that the Biden administration could continue enforcing its tough asylum policy on the southern border for at least several more weeks, while government lawyers appeal a judge’s order striking it down.

The new ruling does not address whether the Biden administration’s policy is lawful. But it keeps the tough border approach in place while the legal challenge by several migrant advocacy groups continues.

In May, the Biden administration put in place the new rules for asylum seekers that presume most migrants who illegally cross from Mexico are ineligible for asylum. The migrant groups sued to prevent the new policy from being enforced.

At the end of July, a federal judge called that new policy “contrary to law” because it violated existing federal statutes and international treaties that require the United States to allow anyone crossing the border to request asylum.

“It presumes ineligible for asylum noncitizens who enter between ports of entry, using a manner of entry that Congress expressly intended should not affect access to asylum,” wrote Judge Jon S. Tigar of the U.S. District Court in Northern California.

In his ruling, the judge said the Biden administration must stop enforcing the new policy, but he paused that order for two weeks to give the government time to appeal his decision.

The decision by the appeals court on Thursday extended the pause, saying the Biden administration should be allowed to continue enforcing its new asylum policy for as long as it takes for the appeals court to rule.

By a vote of 2 to 1, the three-judge panel agreed to expedite its consideration of the government’s appeal and said that briefs from both sides would be due by the end of September at the latest. A hearing will follow.

Representatives of the groups who sued to block the policy said in statements that they remained confident in their case.

“The Biden administration’s asylum ban is illegal and dangerous,” said Anne Peterson, a senior staff attorney at the Center for Gender and Refugee Studies. “The courts have repeatedly struck down these policies as unlawful. We urge the administration to stop defending the ban, accept the district court’s ruling, and immediately reinstate a fair and lawful asylum process for all people seeking refuge at our nation’s doorstep.”

Still, the decision is a victory for President Biden and his immigration officials, who have argued that the tough new rules are a necessary response to recent surges of people fleeing from countries in Central and South America.

“We will continue to apply the rule and immigration consequences for those who do not have a lawful basis to remain in the United States,” said Erin Heeter, a spokeswoman for the Department of Homeland Security. “The rule has significantly reduced irregular migration, and since its implementation on May 12 we have removed more than 85,000 individuals. We encourage migrants to ignore the lies of smugglers and use lawful, safe and orderly pathways.”

The two judges in the majority in the ruling — Judge William A. Fletcher and Judge Richard A. Paez, both appointees of President Bill Clinton — did not explain their reasoning. Judge Lawrence J.C. VanDyke wrote that he agreed with their decision but objected because his two colleagues had been harsher when dealing with cases involving former President Donald J. Trump.

In a five-page dissent, Judge VanDyke, a Trump appointee, wrote that the other judges did not give the former president’s administration the same deference when they were considering several challenges to his immigration policies.

The judge said he saw no difference between Mr. Biden’s approach at the border and a similar policy put in place by Mr. Trump, which the appeals court blocked.

“This new rule looks like the Trump administration’s Port of Entry Rule and Transit Rule got together, had a baby and then dolled it up in a stylish modern outfit, complete with a phone app,” Judge VanDyke wrote.

Paired with the asylum rule, the administration has created new ways for some people to enter the United States with authorization, without having to make the dangerous trek to the border and illegally cross into the United States.

The president has said the combination of those policies has worked to decrease illegal border crossings significantly since the spring, when the numbers hit daily records.

But it is unclear how long those decreases will last. The Washington Post reported this week that illegal border crossings surged again in July, rising more than 30 percent despite the asylum policy and the new opportunities for legal entry.

Mr. Biden has struggled with the border since taking office. As a candidate, he pledged to reverse what he called inhumane policies put in place by Mr. Trump and said he would push for a broad overhaul of the nation’s immigration laws.

He proposed that overhaul on his first day in office, but Congress has refused to act. In the meantime, migration across the hemisphere has dramatically increased.

Before the president’s asylum changes took effect, Border Patrol officials were encountering about 7,500 migrants illegally trying to cross the border each day — record-breaking numbers that were putting severe strains on the immigration officials and border communities.

In his original ruling, Judge Tigar wrote that the Biden administration’s response to that surge was not backed up by existing federal law. Now, the appeals court will decide whether he is right. The case could ultimately end up at the Supreme Court.