The rule aimed to end sales of new fossil-fuel-powered trucks by 2036 and require large fleets to transition to electric or hydrogen models by 2042.

Because Trump is unlikely to approve them, California officials say they had no choice but to abandon the state's groundbreaking rules for zero-emission trucks and cleaner locomotives.

California for decades has driven the U.S. toward less-polluting vehicles. It is the only U.S. state with the power to request a waiver from the EPA to set its own, more stringent