The U.S. Environmental Protection Agency (EPA) has issued a “final disapproval” ruling against a California regulation that calls for emission checks on all vehicles over 14,000 pounds, regardless of where they are registered. 

“The Trump EPA will never back down from holding California accountable and stopping them from imposing unnecessary regulations on the entire nation,” said EPA Administrator Lee Zeldin.

EPA’s decision means California will not be allowed to count this program toward its pollution reduction requirements. The state’s Heavy-Duty Inspection and Maintenance Program, or Clean Truck Check regulation, screens the emissions output of vehicles operating on the state’s roads.

While California said this is to ensure that vehicles’ emissions control systems are properly functioning when traveling on state roadways, the EPA said applying these standards to out-of-state trucks is not a proper use of the federal Clean Air Act. It is also a federal violation over foreign policy matters to regulate vehicles from other countries, such as Canada and Mexico, EPA said.

Following the announcement, the California Air Resources Board said the EPA lacks the authority to regulate the state’s program. Similarly, Gov. Gavin Newsom’s press office said in a social media post that “EPA isn’t stopping California from enforcing California law.”