A federal appeals court has temporarily blocked California from enforcing a new law that would bar federal immigration agents from wearing masks during operations, handing the Justice Department an early win in its challenge to the measure signed by Gov. Gavin Newsom.

U.S. Attorney General Pam Bondi said Thursday that the 9th U.S. Circuit Court of Appeals issued a full stay halting the state's mask ban while litigation continues.

"The 9th Circuit has now issued a FULL stay blocking California's ban on masks for federal law enforcement agents," Bondi wrote in a post on X. 

"Law enforcement officers risk their lives for us, only to be doxxed by radical anti-police activists. Unacceptable," she added.

"This crucial ruling protects our brave men and women in the field. We will not stop fighting bad laws like these in California and across the country."

California's law took effect Jan. 1 and made it a misdemeanor for many law enforcement officers, including federal officers, to wear a mask or other disguise while interacting with the public during official duties, with exceptions for undercover work, medical protection such as N95 respirators, and certain tactical gear.

Supporters dubbed the legislation the "No Secret Police Act" and said it was aimed at improving transparency after masked federal immigration operations drew protests and public scrutiny in 2025, while the Trump administration argued the measure would endanger agents and intrude on federal authority.

The Justice Department sued California in November, arguing the state cannot regulate how federal officers carry out their duties and that the law violates the Constitution's Supremacy Clause.

Earlier this month, U.S. District Judge Christina Snyder in Los Angeles blocked California from enforcing mask restrictions against federal officers, concluding the law unlawfully discriminated against the federal government because it exempted certain state law enforcement agencies while applying to federal agents.

Snyder, however, allowed California to enforce a separate state requirement that law enforcement officers display visible identification showing their agency and badge number, except when working undercover.

Newsom called Snyder's decision upholding the identification requirement "a clear win for the rule of law."

First Assistant U.S. Attorney Bill Essayli also weighed in Thursday.

"The state of California needs to familiarize itself with the Supremacy Clause," he wrote in a post on X.

"It does not have the authority to regulate federal agents. This is another key win for the Justice Department."

The dispute is the latest flashpoint in a long-running clash between California's Democrat leadership and President Donald Trump's administration over immigration enforcement and the limits of state power to constrain federal operations.

California state Sen. Scott Wiener, the bill's author, said after the district court ruling that he would move quickly to revise the law to apply more uniformly across law enforcement agencies, an approach Snyder suggested could change the legal analysis.

The 9h Circuit's stay means the district court's block remains in place as the appellate court considers the government's request for longer-term relief while the case proceeds.

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