WASHINGTON (AP) -- In a major reversal, the new head of the Environmental Protection Agency said he will try to rescind $20 billion in grants awarded by the Biden administration for climate and clean-energy projects.

In a video posted on X, Administrator Lee Zeldin said the EPA would revoke contracts for a still-emerging "green bank" that is set to fund tens of thousands of projects to fight climate change and promote environmental justice.

The program, approved under the 2022 Inflation Reduction Act, is formally known as the Greenhouse Gas Reduction Fund, but is more commonly called the green bank. Two initiatives, worth $14 billion and $6 billion respectively, are intended to offer competitive grants to nonprofits, community development banks and other groups for projects with a focus on disadvantaged communities.

The program is a favorite of Democrats who passed President Joe Biden's signature climate law without a single Republican vote, and former EPA Administrator Michael Regan frequently cited it as one of his major accomplishments.

Republicans in Congress have called the green bank a "slush fund" and voiced concern over how the money will be used and whether there will be sufficient accountability and transparency. The Republican-controlled House approved a bill last year to repeal the green bank and other parts of Biden's climate agenda. The bill was blocked in the Democratic-controlled Senate.

Zeldin, in the video posted Wednesday night, said there will be "zero tolerance of any waste and abuse" at the EPA under his administration. He cited "an extremely disturbing video" on X that features a former EPA staffer stating that the Biden administration was "tossing gold bars off the Titanic" in order to spend billions of taxpayer dollars before President Donald Trump took office.

"The days of irresponsibly shoveling boatloads of cash to far-left activist groups in the name of environmental justice and climate equity are over," Zeldin said. "I've directed my team to find your gold bars, and they found them. Now we will get them back inside of control of government as we pursue next steps."

The video Zeldin cited was posted by Project Veritas, a right-wing organization that often uses hidden cameras to try to embarrass news outlets, labor organizations and Democratic officials. In this case, the Veritas video showed Brent Efron, a former EPA special adviser for implementation, speaking at a bar or restaurant with someone who turned out to be with the group. Efron has since left the EPA.

Clean energy advocates denounced Zeldin's action as a political stunt and said he was illegally attempting to revoke spending approved by Congress for partisan reasons. They pledged to challenge the directive in court.

"This is not just an attack on clean energy investments -- it's a blatant violation of the Constitution," said Lena Moffitt, executive director of Evergreen Action, an environmental group that supports the green bank. "The Trump team is once again trying to illegally slash programs meant to help American families to fund tax cuts for billionaires."

The money has already been awarded to eight nonprofits, including the Coalition for Green Capital, Climate United Fund, Power Forward Communities, Opportunity Finance Network, Inclusiv and the Justice Climate Fund. Those organizations have partnered with a range of groups, including Rewiring America, Habitat for Humanity and the Community Preservation Corporation.

Former Vice President Kamala Harris announced the grant awards last year at an event in Charlotte, North Carolina.