Stellantis NV, owner of the Jeep and Ram brands, is restricting sales of gasoline-powered vehicles in 14 states to comply with stricter emissions standards in California and 13 other states that have adopted similar rules.

Car buyers in those 14 states who specifically order gasoline-fueled vehicles from Stellantis can still buy them, but the automaker is limiting its allocation of cars, SUVs and trucks with internal combustion engines to its dealer network in those places, a company spokesman said Friday.

“We may need to adjust vehicle allocations among the California and non-California states to ensure that Stellantis complies with the unique standards in the California states,” the automaker said in an emailed statement.

California standards governing emissions from cars and light trucks through model year 2025 are followed by at least 13 other states representing more than a third of the US vehicle market. Environmental advocates say those requirements, which track an approach the state charted with the Obama administration roughly a decade ago, are tougher than federal standards.

The sales restrictions, which began in April, stem from a legal battle between the California Air Resources Board and the Trump administration over California’s authority to set its own clean-air rules, the company said.

Read More: Biden Reverses Trump Crackdown on California Car Pollution Rules

Officials at CARB didn’t have an immediate comment. Automotive News reported on the restrictions earlier Friday.

Stellantis also said it may be forced to send fewer gasoline cars to CARB-aligned states and fewer electrified vehicles to the remaining states.

“This may impact our dealer network’s ability to order or receive shipments of certain vehicles from time to time, including sold orders,” it said.