(CNN) A federal judge in Texas has put on hold for now the Biden administration's most recent attempt to end the so-called "Remain in Mexico" program.
US District Judge Matthew Kacsmaryk is pausing the termination of the program that was outlined in an October 2021 policy memo while litigation around that memo continues.
The ruling marks a setback in President Joe Biden's effort to end the controversial Trump-era policy, which sends certain non-Mexican citizens who entered the US back to Mexico -- instead of detaining them or releasing them into the US -- while their immigration proceedings played out.
An administration official said that the "Secretary of Homeland Security was well within his authority to terminate the prior Administration's program."
"We disagree with this decision and are determining next steps," the official said.
The Remain in Mexico program, formally known as Migrant Protection Protocols, is separate from Title 42, which is set to end next week. That authority, which was heavily criticized by public health experts and immigrant advocates, has largely barred asylum at the US-Mexico border.
In June, the Supreme Court ruled 5-4 the Biden administration had the discretion to end the Remain in Mexico program, rejecting arguments from Republican states that immigration law required the program to remain in effect and granting an initial victory for the Biden immigration agenda in its efforts to reverse Trump's hardline immigration policies.
But the Supreme Court sent the case back to Kacsmaryk to consider whether the rollout of the October 2021 memo complied with the Administrative Procedure Act -- which requires that agencies take certain procedural steps when implementing policy -- in how it went about unwinding Migrant Protection Protocols.
In light of the Supreme Court's June ruling, the Biden administration had already begun unwinding the Remain in Mexico policy, according to Gianna Borroto, a senior litigation attorney with the American Immigration Council. Kacsmaryk's new order does not command the United States to restart negotiations with Mexico about re-implementing the program, raising questions about how the administration will respond from a practical standpoint.
"We don't have an agreement with Mexico for Mexico to accept people being returned under MPP," Borroto told CNN.
The program, which was first implemented in 2019 under then-President Donald Trump, has been criticized by immigrant-rights advocates, who argue that it's inhumane and that it exposes asylum seekers with credible claims to dangerous and squalid conditions in Mexico.
Before the Trump administration put the "Remain in Mexico" program in place, no other administration had embraced such an approach toward non-Mexican asylum-seekers that required them to stay in Mexico over the course of their immigration court proceedings in the United States. Biden campaigned on ending the policy and has said it "goes against everything we stand for as a nation of immigrants."
Biden has grappled with a growing number of border crossings over the course of his administration amid mass migration in the Western Hemisphere. The Department of Homeland Security, though, has maintained that the "Remain in Mexico" policy comes at a steep human cost and is not an effective use of resources.
Ken Paxton, the attorney general of Texas -- which brought the legal challenge with Missouri to the termination of MPP -- issued a statement Friday praising Kacsmaryk's new decision.
"The court made the right decision here in protecting Remain-in-Mexico, and I look forward to fighting to make sure the program is secured indefinitely," Paxton said.
This story has been updated with additional details.