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WASHINGTON — Canada has signaled a willingness to buck one of President Trump’s most significant environmental rollbacks — a major weakening of auto pollution standards — by signing a clean-car deal with California, the state leading the fight against the rollback.

Wednesday’s agreement, which pledges to advance the use of clean and electric cars, lacks binding specifics. Nevertheless, Canada’s decision to publicly align itself with California and its climate-change policies inserts the government of Prime Minister Justin Trudeau into a high-profile battle being waged over Mr. Trump’s weakening of rules designed to combat climate change.

“Working with California is a way to move forward and share best practices and align our standards,” said Catherine McKenna, the Canadian environment minister, on a telephone call with reporters. “California has been an inspiration when it comes to clean fuel standards. That is where the world is going.”

Traditionally, Canada has aligned its auto emissions standards with federal rules in the United States. However, several analysts said they saw Wednesday’s announcement as a clear step toward a more concrete shift in which Canada could potentially switch to the environmentally stricter standards of California and other states.