A Texas federal judge on Tuesday temporarily blocked President Joe Biden’s order to halt for 100 days the deportations of certain immigrants, delivering an early blow to the new administration’s immigration agenda.

U.S. District Judge Drew B. Tipton of the Southern District of Texas found that the administration’s moratorium, a memorandum issued on Biden’s first day in office to fulfill a campaign promise, is likely illegal.

The moratorium “not only fails to consider potential policies more limited in scope and time, but it also fails to provide any concrete, reasonable justification for a 100-day pause on deportations,” Tipton, an appointee of President Donald Trump, said in his order.

Under the moratorium, signed by acting Homeland Security Secretary David Pekoske, the U.S. government is barred from deporting certain foreign citizens who entered the U.S. before Nov. 1, while the new administration considers immigration enforcement priorities.

Tipton’s order, which halts the moratorium for 14 days, applies nationwide. The judge noted, however, that the sweeping effect of his order is “not necessarily permanent” and something the court “is willing to revisit” as the case progresses.

Texas Attorney General Ken Paxton praised the court’s ruling as a “much-needed remedy.”

“I commend the Court for prioritizing the law and safety of our citizens, and I will continue to defend Texas against the unlawful and unconstitutional actions of President Biden and his Administration,” he said in a statement. 

A representative for the White House did not immediately return a request for comment Tuesday.

Cody Wofsy, an attorney with the American Civil Liberties Union, which filed a friend-of-the-court brief opposing Texas’ challenge, slammed Tipton’s ruling in a statement Tuesday. “This initial, tentative, and hasty decision is incorrect, and we are confident it will be set aside as the case proceeds,” he said.

The court’s ruling marks an early loss for the Biden administration as it seeks to reverse some of Trump’s border restrictions and adopt a new tone on immigration.

On Jan. 20, just hours after his inauguration, Biden signed a series of immigration-related executive orders. In addition to his administration’s memo pausing deportations, the orders halted border wall construction, rescinded Trump’s travel ban affecting Muslim-majority nations and affirmed his commitment to strengthen the Deferred Action for Childhood Arrivals program.

Biden has also proposed immigration overhaul legislation that would create a path to citizenship for millions of undocumented immigrants in the U.S.

But just as Democratic-led states like New York and California frequently challenged the Trump administration on its restrictionist immigration policies, Texas quickly emerged as a key player in fighting the Biden administration as it seeks to loosen them.

The Lone Star state swooped into court Friday on the first day Biden’s deportation pause took effect, arguing that the moratorium violated an agreement struck with the U.S. Department of Homeland Security in early January, under the prior administration, to consult Texas on any decisions to reduce immigration enforcement.

Earlier Tuesday, Texas also re-upped its efforts in a separate court case to strike down DACA, which gives work permits and deportation relief to certain immigrants brought to the United States, in light of Biden’s executive order to “preserve and fortify” the program.