President Donald Trump, joined Thursday by Environmental Protection Agency Administrator Lee Zeldin, announced that his administration is rescinding a 2009 determination that classified greenhouse gas emissions from fossil fuels as a threat to public health, a designation that has underpinned federal climate regulations for more than a decade.

Trump described the move as a historic rollback of federal rules and predicted sweeping financial relief for Americans.

Trump called the repeal “the single largest deregulatory action in American history” and said it would “save American consumers trillions of dollars.”

Speaking from the Roosevelt Room at the White House, the president sharply criticized the original policy, which was adopted during the Obama administration, arguing that it harmed the domestic auto sector and increased costs for drivers.

“We are officially terminating the so-called endangerment finding, a disastrous Obama-era policy that severely damaged the American auto industry and massively drove up prices for American consumers,” Trump said in the White House Roosevelt Room.

He added that the repeal takes effect immediately and extends beyond the original finding itself to other related emissions standards enacted over the past decade.

“Effective immediately, we are repealing the ridiculous endangerment finding and terminating all additional green emission standards imposed unnecessarily on vehicle models and engines between 2012 and 2027 and beyond.”

According to Trump, undoing the policy could reduce the price of new vehicles by thousands of dollars. He also took aim at certain automotive features that he said were mandated as a result of emissions rules.

“Under the endangerment finding, they forced the hated start-stop feature onto American consumers, which unnecessarily shuts off a car’s engine. When you stop at a red light, in other words the engine goes off. That’s great,” Trump said.

Zeldin echoed the president’s remarks, characterizing the action as a major pushback against expansive federal authority.

Zeldin said that the Republicans were scrapping the “holy grail of federal regulatory overreach.”