The move, which will impact the agency's 10 regional offices and headquarters, was first reported by the New York Times and confirmed by Environmental Protection Agency (EPA) chief Lee Zeldin on Wednesday.

"The problem is that in the name of environmental justice, a fortune has been sent to left-wing activist groups," Zeldin told reporters.

"President Trump wants us to help usher in a golden age in America that is for all Americans, regardless of race, gender, background," he added.

Environmental groups reacted with anger.

"President Trump and his allies have no regard for the well-being of people living in America and care only about protecting the profits of polluters," said Chitra Kumar, of the Union of Concerned Scientists.

"This abhorrent move will leave those living, working, studying, and playing near polluting industries, smog-forming traffic, and contaminated waterways and soil, with little support from the very agency they rely on to enforce protective law."

Former president Joe Biden made environmental justice a central pillar of his green agenda.

His Justice40 initiative -- since rolled back by Trump -- aimed to direct 40 percent of federal investments in climate, clean energy, and affordable housing to historically marginalized communities.

The Inflation Reduction Act, Biden's signature climate law, allocated $3 billion to the Office of Environmental Justice and External Civil Rights, which was established under Republican former president George H.W. Bush in 1992.

Zeldin's EPA on Monday announced it was cutting 400 grants totaling $1.7 billion related to environmental justice initiatives.

Last week, Trump's Justice Department also announced it was dropping a lawsuit on behalf of the EPA against Denka Performance Elastomer concerning its neoprene manufacturing facility in LaPlace, Louisiana.

The plant is located in a stretch of Louisiana known as "Cancer Alley," which accounts for around a quarter of US petrochemical production and has among the highest cancer rates in the country.

Zeldin's EPA plans to cut 65 percent of its roughly 15,000 staff, leaving around 5,000 employees.

The former Republican congressman said there were a "few hundred" probationary employees that had already departed, and the remaining staff were being asked to justify their positions.

"I want to know what every employee would define as their job description, what they believe their job to be, who they believe is their supervisor, what they believe their supervisor's job is," he said, adding these answers would help determine the next rounds of staffing cuts.