The U.S. Environmental Protection Agency initiated a buyout program on Thursday to reduce staff numbers as the agency seeks to refocus its agenda on reducing regulation, according to an internal memo to staff seen by Reuters.

The memo was sent to all EPA employees on Thursday afternoon as EPA Administrator Scott Pruitt joined President Donald Trump at the White House where the Republican president announced the United States would withdraw from the Paris climate agreement.

The memo, sent by acting Deputy Administrator Mike Flynn, said the agency wanted to complete the buyout program by September.

"Early outs and buy outs ... can help us realign our workforce to meet changing mission requirements and move toward new models of work," the memo said. "The authority encourages voluntary separations and helps the Agency complete workforce restructuring with minimal disruption to the workforce."

The EPA saw the biggest cuts in Trump's 2018 budget proposal, with a 31 percent reduction in budget and the elimination of over 3,200 employees.

That budget proposal would "reduce redundancies and inefficiencies and focus on our core statutory mission," an EPA spokeswoman said last month.

In the memo, Flynn said the agency planned to submit its buyout proposal to the White House Office of Management and Budget for approval later in June and would work with it to "expedite the review process."