A three-judge panel of the 9th Circuit Court of Appeals ruled unanimously Thursday that most of three California sanctuary laws limiting cooperation with federal immigration authorities can continue to be enforced, rejecting the bulk of a suit brought by the Trump administration.

The judges declined to block the most contentious law, Senate Bill 54, which prohibits police and sheriff's officials from notifying immigration authorities when immigrant inmates are released from prison. In the opinion, Judge Milan D. Smith Jr. wrote: "We have no doubt that makes the jobs of federal immigration authorities more difficult." However, he added that the law "does not directly conflict with any obligations" placed on state or local governments by federal law "because federal law does not mandate any state action."

The court also upheld a California law, Assembly Bill 450, mandating that employers alert employees of any upcoming federal immigration inspection share the inspection results with employees who may not be authorized to work in the U.S. Judge Smith, who was nominated to the federal bench by George W. Bush, ruled that the state law "imposes no additional or contrary obligations that undermine or disrupt the activities of federal immigration authorities."

The court did block part of Assembly Bill 103, which requires the state to review detention facilities where immigrants are held, ruling that a provision requiring the state to review circumstances surrounding the apprehension and transfer of detainees puts an impermissible burden on the federal government.

"Only those provisions that impose an additional economic burden exclusively on the federal government are invalid," wrote Judge Smith.

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The Justice Department sued California over its sanctuary laws in March 2018, with then-Attorney General Jeff Sessions saying that they hindered cooperation between federal and local law enforcement and prevents the government from enforcing federal immigration law. U.S. District Judge John Mendez previously threw out the federal government's challenge to Senate Bill 54, Assembly Bill 103 and part of Assembly Bill 450, but rejected a provision in the latter law that fines private employers who voluntarily allow immigration agents to visit workplaces.

California officials have said the immigration laws promote trust between immigrant communities and law enforcement.

California Attorney General Xavier Becerra, who has repeatedly sued the Trump administration, mostly over immigration and environmental decisions, said the ruling shows that states' rights "continue to thrive."

"We continue to prove in California that the rule of law not only stands for something but that people cannot act outside of it," Becerra said in a statement.

The Justice Department had no immediate comment.

Fox News' Adam Shaw and The Associated Press contributed to this report.