California’s governor, Jerry Brown, denounced Jeff Sessions on Wednesday after the US attorney general spoke in the state about a lawsuit over policies that limit cooperation with federal immigration authorities.

Brown told reporters shortly after Sessions’s speech to law enforcement officials on Wednesday that it was unprecedented for the attorney general to “act more like Fox News than a law enforcement officer”.

The Democrat accused Sessions of lying and of trying to appease Donald Trump. He said Sessions’s actions were about dividing America.

Earlier, Sessions, escalating the Trump administration’s rhetoric against the most populous US state, accused California of obstructing federal immigration enforcement efforts and vowed to stop the state’s defiance.

Sessions made the remarks to a law enforcement group a day after Trump’s justice department sued Democratic-governed California over so-called sanctuary policies that try to protect illegal immigrants from deportation.

“California is using every power it has – and some it doesn’t – to frustrate federal law enforcement. So you can be sure I’m going to use every power I have to stop them,” Sessions, the top US law enforcement officer, said in prepared remarks.

“In recent years, California has enacted a number of laws designed to intentionally obstruct the work of our sworn immigration enforcement officers – to intentionally use every power it has to undermine duly established immigration law in America,” Sessions added.

Sessions said US Immigration and Customs Enforcement agents carry out federal law and that “California cannot forbid them or obstruct them in doing their jobs.”

The lawsuit, filed late on Tuesday in federal court in Sacramento, takes aim at three state laws passed last year that the justice department contends violate the US constitution and the supremacy of federal law over state law.

Trump has made fighting illegal immigration and cracking down on illegal immigrants already in the United States a signature issue, first as a candidate and now as president.

“Immigration law is the province of the federal government,” Sessions said. “I understand that we have a wide variety of political opinions out there on immigration, but the law is in the books and its purpose is clear,” Sessions added.

“There is no nullification. There is no secession. Federal law is the supreme law of the land.”

Sessions, who was speaking at a California Peace Officers Association conference in Sacramento, has made combating illegal immigration one of his top priorities since taking over the justice department in February 2017. A key part of that effort involves a crackdown on primarily Democratic-governed cities and states that Sessions calls “sanctuaries” that protect illegal immigrants from deportation.

Governor Brown in October signed into law a bill that prevents police from inquiring about immigration status and curtails law enforcement cooperation with immigration officers.