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's Advanced Clean Fleets rule aimed to set timelines for operators of trucks carrying everything from U.S. mail and UPS packages to 40-foot containers of goods and other cargo, to switch to zero-emissions vehicles such as those powered by electric batteries.