Mandy Gunasekara, who pressed for President Trump to exit the Paris climate agreement as the Environmental Protection Agency’s top air-policy adviser, is poised to return to the agency as its next chief of staff, according to two individuals briefed on the matter.

Gunasekara left the EPA a year ago to start what she called a “pro-Trump nonprofit” in her home state of Mississippi. As head of the advocacy group Energy 45, she has argued on behalf of the president’s support for fossil fuels and other energy policies, writing that his approach “has brought both economic prosperity and cleaner air and water.”

After joining the EPA in March 2017, Gunasekara oversaw the agency’s Office of Air and Radiation on an acting basis for nearly eight months under then-Administrator Scott Pruitt. Trained as a lawyer, she played a key role in working to scale back federal rules aimed at cutting greenhouse gas emissions and other forms of pollution, including replacing the Obama-era Clean Power Plan and federal gas-mileage standards.

“By ending President Trump’s energy policies, Democrats will destroy America’s economy, drive up energy costs, and end millions of American jobs,” Gunasekara tweeted Wednesday, along with a photo of Rep. Alexandria Ocasio-Cortez (D-N.Y.) and the words “Wants 19 Million Americans To Lose Their Jobs.”

The EPA’s chief of staff, Ryan Jackson, is stepping down later this month to work as the top lobbyist for the National Mining Association. The two individuals briefed on Gunasekara’s hiring spoke on the condition of anonymity because the decision had not been publicly announced.

Gunasekara declined to comment. Asked about the matter Thursday, agency spokesman Michael Abboud said in an email, “Ryan Jackson is Chief of Staff at EPA until February 21st, at which time Michael Molina will serve as Acting Chief of Staff.”

Samantha Dravis, who headed EPA’s Office of Policy from February 2017 to April 2018, praised Gunasekara as someone who can deliver results.

“Mandy has a unique ability to drive an agenda forward and actually get things done," said Dravis, now a senior vice president at Clout Public Affairs. "She’s someone who brings people together and is universally well- liked and respected by her colleagues at EPA and on the Hill.”

Sierra Club spokesman Adam Beitman, however, criticized Gunasekara’s record.

"Now that Gunasekara’s efforts to try and greenhouse gaslight the country into believing that Trump is an environmentalist have failed, we’re not surprised she opted to rejoin Andrew Wheeler in attempting to roll back as many clean air, clean water and climate protections as possible,” he said.

Gunasekara shares a key credential with other senior EPA staffers serving under Trump, including Jackson and Administrator Andrew Wheeler: They all have worked at some point for Sen. James M. Inhofe (R-Okla.). Inhofe has been an outspoken critic of climate change regulations and the author of a book titled “The Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future.”

Gunasekara had not worked for Inhofe long when, in early 2015, he asked her to hand him a snowball on the Senate floor, as he mocked the idea that the planet was warming in troubling ways.

Upon leaving the EPA last February, Gunasekara wrote in a resignation letter to Trump that “working on your America First agenda for the past two years was the honor of my life.”

She praised Trump’s decision to withdraw from the international Paris climate agreement and scale back regulations on everything from gas-mileage standards to carbon dioxide emissions from the nation’s power plants.

“Historic resistance from Democrats, the media and even some Republicans has made your accomplishments even more monumental,” Gunasekara wrote, adding, “I am increasingly concerned with the rhetoric from the far-left supportive of Venezuelan-style socialism, government take-overs and crony ‘green new deals’ that do little for the environment and threaten our economic success.”

The group she subsequently founded, Energy 45, does not disclose its donors. Gunasekara has written op-eds for newspapers such as USA Today and appeared on television networks such as Fox News, aiming to serve as a counterweight to critics of the Trump administration’s efforts to dismantle environmental safeguards.

“I think what Republicans are starting to understand is, we need to be better about communicating the good work that we’re doing,” she said in an interview with The Washington Post last year. “I always say, we’re right on the policy, we’re right on the facts,” she added. “But what we’re not great at is conveying that.”