And his budget director made clear the administration has no intention of going back.
Asked at the White House about the cuts to climate change-related programs, Office of Management and Budget Director Mick Mulvaney said those programs are "a waste of your money."
"Regarding the question as to climate change, I think the President was fairly straightforward. We're not spending money on that anymore. We consider that to be a waste of your money to go out and do that.' So that is a specific tie to his campaign," Mulvaney said.
Sources inside the EPA told CNN that they anticipated at least 25% in budget cuts, and possibly deeper. Trump delivered: 31%.
The proposal would cut $2.6 billion from the agency, for a 2018 budget of $5.7 billion, and result in 3,200 fewer jobs, according to the White House outline.
Climate change programs were targeted, including discontinuing funding for the Clean Power Plan, President Barack Obama's signature environmental regulation intended to curb global warming. Funding would also be cut for international climate change programs and climate change research and partnership programs.
The plan aims to reduce EPA's compliance enforcement budget by $129 million, and eliminate funding for regional efforts like Great Lakes restoration, Chesapeake Bay and other geographic programs by $427 million.
Trump also proposes eliminating funding for 50 EPA programs including Energy Star ,targeted airshed grants the endocrine disruptor screening programs and infrastructure assistance to Alaska native villages and Mexico border.
Presidential budget plans outline the administration's priorities but must be approved by Congress and are always changed in the process. The Trump administration will release its full budget in May.
Discussions have been ongoing for weeks regarding these cuts, which are expected to include grants to states aimed at protecting air, water and land.
Mulvaney Wednesday that "core functions of the EPA can be satisfied with this budget," but agency advocates disagree.
"It is a sad day when a group of millionaires and billionaires in Washington can decide what's best for America's health and environment," said John O'Grady, head of the union that represents EPA employees. "How can this administration tell America that we will have clean air and clean water with a 25% reduction in US EPA's budget?"
He added: "The US EPA is already on a starvation diet, with a bare-bones budget and staffing level. The administration's proposed budget will be akin to taking away the Agency's bread and water."
Trump's $1.1 trillion budget outline proposes a $54 billion increase in defense spending and corresponding cuts to non-defense spending at the State Department, the Department of Housing and Urban Development, the EPA and the wholesale elimination of other federal programs.