car makers strike deal with California

WASHINGTON — Four automakers from three continents have struck a deal with California to produce more fuel-efficient cars for their US fleets in coming years, undercutting one of the Trump administration’s most aggressive climate policy rollbacks.

The compromise between the California Air Resources Board and Ford, Honda, Volkswagen, and BMW of North America came after weeks of secret negotiations and could shape future US vehicle production, even as White House officials aim to relax gas mileage standards for the nation’s cars, pickup trucks, and SUVs.

Mary Nichols, California’s top air pollution regulator, said in an interview Wednesday that she sees the agreement as a potential ‘‘olive branch’’ to the Trump administration and hopes it joins the deal, which she said gives automakers flexibility in meeting emissions goals without the ‘‘massive backsliding’’ contained in the White House proposal.

In a joint statement, the four automakers said their decision to hash out a deal with California was driven by a need for predictability, as well as a desire to reduce compliance costs, keep vehicles affordable for customers, and be good environmental stewards.

The deal comes as the Trump administration is working to finalize a huge regulatory rollback that would freeze mileage requirements for cars and light trucks next fall at about 37 miles per gallon on average, rather than raising them over time to about 51 mpg for 2025 models — the level to which the industry and government agreed during the Obama administration. The proposal would also revoke California’s long-standing authority to set its own rules under the Clean Air Act, a practice the federal government has sanctioned for decades.

The White House argues that more lenient standards would lower the sticker price of vehicles and encourage Americans to buy newer, safer cars. But California has vowed to enforce stricter requirements to lower greenhouse gas emissions, and the auto industry itself has implored the Trump administration to try to find common ground with California.

Trump officials quickly rejected the idea of embracing the new deal as a blueprint for federal mileage goals, and said it was pressing ahead with its rollback.

‘‘The federal government, not a single state, should set this standard,’’ said White House spokesman Judd Deere in an e-mail.

Environmental Protection Agency spokesman Michael Abboud said of the agreement, ‘‘This voluntary framework is a PR stunt that does nothing to further the one national standard that will provide certainty and relief for American consumers.’’

And officials from the National Highway Traffic Safety Administration, which is co-writing federal tailpipe standards, noted in a statement that the administration’s proposal doesn’t prevent manufacturers from building more efficient vehicles if they so choose.

Under the new accord, the four companies, which represent roughly 30 percent of the US auto market, have agreed to produce fleets averaging nearly 50 mpg by model year 2026. That’s just one year later than the target set under the Obama administration, which argued that requiring more-fuel-efficient vehicles would improve public health, combat climate change, and save consumers money at the gas pump without compromising safety.

The share of the US auto market affected by the new terms could grow significantly if other automakers also join the deal. Last month, the Canadian government also pledged to align mileage requirements for its auto market with California rather than the Trump administration.