President Donald Trump said Wednesday that his administration is barring California from setting its own auto emissions standards, setting up a fresh struggle over the president's push to unravel restrictions on businesses.

In tweets announcing the move, Trump said the White House "is revoking" a federal waiver that allowed the state to craft its own rules on greenhouse gas emissions from vehicles. The president argued he blocked California's ability to do so "in order to produce far less expensive cars for the consumer, while at the same time making the cars substantially SAFER."

He also contends "there will be very little difference in emissions" under federal rules his administration plans to release than under standards California agreed to with automakers.

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Trump took the step over the protests of Democratic officials and activists in California, who argue it inhibits efforts to fight climate change and improve public health. California Attorney General Xavier Becerra has said the state would file a lawsuit to stop the Trump administration from pulling its waiver.

"Our message to those who claim to support states' rights: Don't trample on ours," Becerra told reporters Wednesday. He added: "We're prepared to lead, we're prepared to fight. We'll do what we must."

Speaking to reporters Wednesday, the state's Democratic governor, Gavin Newsom, said, "We are the pace car, as it relates to environmental stewardship." But he said his state is "dealing with an administration that lays claim, and a Republican Party that lays claim, to supporting free enterprise. The irony of that shouldn't be lost on anyone."

The Trump administration's actions are "not free enterprise," Newsom said. "That's not about states' rights. That's about bullying and intimidation."

Trump has moved to dial back Obama-era carbon greenhouse gas rules as he contends the restrictions have held back American businesses. In his tweets Wednesday, he pitched his latest move as a way to create a "new and uniform standard" and boost job growth.

"Automakers should seize this opportunity because without this alternative to California, you will be out of business," Trump claimed, without citing why the state's rule would have put automakers out of business.

Critics say his plans turn a blind eye to the dire threat posed by climate change.

The Trump administration is set to announce proposals to set looser standards for auto emissions than those sought by his predecessor. In July, California signed a deal with BMW, Ford, Honda and Volkswagen that would set tougher standards than those desired by Trump.

The automakers prepared to make cars nationwide that would meet the state's restrictions. Regulators under Trump have supported keeping emissions standards for new cars and trucks at 2020 levels through 2026, according to Reuters.

"A balanced fuel economy regulation is critical for the health of the U.S. auto industry," the Association of Global Automakers said in a statement. The group continued its call for a "unified national standard that continues the industry's significant progress in improving motor vehicle fuel economy, and that rewards investments in next-generation fuel-savings technologies."

Ahead of Trump's announcement Wednesday, Sen. Dianne Feinstein, D-Calif., criticized the administration's proposal. She said she "strongly" support Becerra's decision to go to court "to stop this ill-advised move."

House Minority Leader Kevin McCarthy, R-Calif., told reporters that he hoped the state would side with the president, as he does not think the country should have more than one emissions standard.

On Wednesday, UCLA School of Law environmental law expert Julia Stein wrote that "the administration is barreling forward into unprecedented territory ... where it will find itself on shaky footing from both a policy and a legal perspective."

"It's just not smart policy. It's also unprecedented, unauthorized by the Clean Air Act, and unsupported by prior agency and court decisions," wrote Stein, project director of the Emmett Institute on Climate Change and the Environment at the UCLA School of Law.

The fight is only the latest between California and the Trump administration. The state has already sued the administration dozens of times, over issues including the president's ban on travelers from several predominantly Muslim countries and his efforts to build barriers on the U.S.-Mexico border.

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— CNBC's Kevin Breuninger contributed to this report.