The Biden administration wants automakers to raise gas mileage and cut tailpipe pollution between now and model year 2026, and it has won a voluntary commitment Thursday from the industry that electric vehicles will comprise up to half of US sales by the end of the decade.

The move marks a consequential push by the administration to combat climate change and tackle the nation’s biggest source of greenhouse gas emissions. It also reflects a delicate balance to gain both industry and union support for the environmental effort, with the future promise of new jobs and billions in new federal investments in electric vehicles.

On Thursday the administration announced there would be new mileage and anti-pollution standards from the Environmental Protection Agency and Transportation Department, part of Biden’s goal to cut US greenhouse gas emissions in half by 2030. It said the auto industry had agreed to a target that would see 40% to 50% of new vehicle sales comprises of electric cars by 2030.

“The future of the auto industry is electric — and made in America,” Biden wrote on Twitter Thursday to announce the move.

Both the regulatory standards and the voluntary target are included in an executive order that Biden plans to sign Thursday.

The new rulemaking from the EPA represents the Biden administration’s first major effort to use the federal government’s regulatory authority to cut carbon emissions. It also is a repudiation of a freeze on fuel-efficiency standards imposed under Donald Trump, one of the former president’s biggest environmental rollbacks. Trump scaled back the requirements put in place under the Obama administration in 2012, which would have ramped up average fuel economy to 54.5 miles per gallon by model year 2025.

The Biden administration expects its actions to conserve about 200 billion gallons of gasoline and forestall around 2 billion metric tons of carbon pollution, the Washington Post reported.

In a signal of industry support, Biden will be flanked by the chief executives of the nation’s three largest automakers as well as the head of the United Auto Workers. The automakers will follow through on their pledge to boost electric car production on the condition that Congress passes a $1 trillion infrastructure bill that calls for $7.5 billion for a national network of electric vehicle charging stations.

But the goal faces a host of challenges.

Experts say it will not be possible for electric vehicles to go from niche product – which accounted for only 2 .2% of US auto sales last year – to mainstream without making electric charging stations as ubiquitous as corner gas stations are today. And while labor leaders will attend the White House event, they remain concerned about a wholesale shift to electric vehicles, which require fewer workers to assemble.

But without a radical change to the type of vehicles Americans drive, it will be impossible for Biden to meet his ambitious pledge to cut planet-warming emissions by 50 percent from 2005 levels by the end of this decade. Gasoline-powered cars and trucks are the largest single source of greenhouse gases produced in the United States, accounting for 28 percent of the nation’s total carbon emissions.

Several US automakers already have announced similar electric vehicle sales goals to those in the deal with the government. Last week, for instance, Ford’s CEO said his company expects 40% of its global sales to be fully electric by 2030. General Motors has said it aspires to sell only electric passenger vehicles by 2035. Stellantis, formerly Fiat Chrysler, also pledged over 40% electrified vehicles by 2030.

The voluntary deal with automakers defines an electric vehicle as plug-in hybrids, fully electric vehicles and those powered by hydrogen fuel cells.

US environmental groups said the administration should move faster.

“This proposal helps get us back on the road to cleaning up tailpipe pollution,” Simon Mui of the Natural Resources Defense Council told the Associated Press. “But given how climate change has already turned our weather so violent, it’s clear that we need to dramatically accelerate progress.”

Dan Becker, director of the safe climate campaign for the Center for Biological Diversity, told AP that ““We urgently need to cut greenhouse gas pollution, and voluntary measures won’t cut it.”