The Environmental Protection Agency has sent the White House a proposal widely expected to scale back future fuel-economy standards for cars and trucks.
EPA spokesman Jahan Wilcox confirmed Thursday that the agency has sent proposed new standards to the Office of Management and Budget for review.
The move is one of the required steps before a federal rule is adopted.
Landmark rules set by the Obama administration mandated that cars and light trucks average more than 50 miles per gallon by 2025, a move to fight climate-changing emissions from automobile exhaust.
Any rollback in U.S. fuel-economy efforts would affect the automobile industry globally, and weaken efforts to curb pollution and climate-changing emissions.
There were no immediate details on the revised rules sent to the White House. Wilcox said the agency would not comment while the proposed changes go through federal review.
EPA administrator Scott Pruitt had signaled plans for a rollback in the Obama fuel-economy standards, saying this spring the standards were "too high."
President Donald Trump in January said his administration was cutting rules on Detroit automakers and would "get Motor City revving its engines again."
Just what the new rules would look like has been the topic of months of wrangling among federal agencies, automakers, states and others.
Pruitt has not specified what limits would be put in place. But he said in April the EPA and the National Highway Traffic Safety Administration would establish a standard that "allows auto manufacturers to make cars that people both want and can afford — while still expanding environmental and safety benefits of newer cars."