Ypsilanti, Michigan - President Donald Trump says his administration will re-examine federal requirements governing the fuel efficiency of cars and trucks, moving forcefully against Obama-era environmental regulations that Trump says are stifling economic growth.
Trump revealed his plans on Wednesday at an automotive testing centre near Detroit, where he also met with auto company executives and workers.
"This is going to be a new era for American jobs and job creation," Trump said at a round-table meeting.
The EPA under Obama had promulgated a rule for cars and trucks requiring a fleet-wide average of 6.57 litres per 100km in real-world driving by 2025.
Trump's decision, while having no immediate effect, requires the Environmental Protection Agency to determine no later than April 2018 whether that standard is appropriate. If the EPA determines that it's not, the agency will submit a new proposal next year.
"My administration will work tirelessly to eliminate the industry-killing regulations, to lower the job-crushing taxes and to ensure a level playing field for all American companies and workers," Trump said at the American Centre for Mobility, which produced Consolidated B-24 Liberator bombers during the Second World War and is being converted into an automotive testing and product development facility.
Trump's announcement is expected to set the stage for weaker fuel-efficiency standards as well as drawn-out legal battles with environmental groups and states such as California that have adopted their own tough tailpipe standards.
EPA Administrator Scott Pruitt said: "These standards are costly for automakers and the American people." He promised a "thorough review" that will "help ensure this national program is good for consumers and good for the environment".
California Governor Jerry Brown accused Trump and Pruitt of trying to weaken auto-emission standards in what he called "an unconscionable gift to polluters".
Brown and New York Attorney General Eric Schneiderman announced their states would be intervening in a lawsuit challenging the EPA rule. New York is among more than a dozen, mostly Northeastern states that have adopted California standards.
The Alliance of Automobile Manufacturers, which represents a dozen major manufacturers including General Motors, Ford, Fiat Chrysler and Toyota, praised Trump's action. It said he was creating an opportunity for federal and state officials to "reach a thoughtful and coordinated outcome predicated on the best and most current data".
Environmental groups said Trump and his team appeared intent on easing fuel-efficiency requirements set by Obama.
Safe Climate Campaign director Dan Becker said: "If they succeed we'll pay more at the pump, depend more on oil from bad countries, drive up the trade deficit and pollute our kids' atmosphere."
In 2012 the Obama administration set fuel-consumption regulations for model years 2017-2025 and agreed to complete a midterm evaluation by 2018. But seven days before Obama left office, the EPA decided to keep the stringent requirements it had set in place for model years 2022 to 2025. The industry balked at the decision, insisting it was rushed through to beat the change in administrations.
Trump said he would put that midterm review back on track, so officials can spend another year studying the issue before setting new standards in 2018. .
The auto alliance last month urged Pruitt to relax the standards, saying they will drive up car costs, price customers out of the market and depress the industry. Trump told the auto executives that while he's attuned to concerns about the environment, he doesn't want to stifle jobs.
"We want you to make great cars," he said. "And if it takes an extra thimble full of fuel, we don't want that to stop making it."