Live Updates: Trump Proposes Slashing Domestic Spending to the Lowest Level of the Modern Era

Mr. Trump proposed cutting funding for some federal law enforcement, including the F.B.I. He called on lawmakers to slash money meant to police tax evasion at the Internal Revenue Service. He recommended striking billions in funds that help finance clean water projects. And the president reserved some of his deepest cuts for education, health and science, including the National Institutes of Health and the Centers for Disease Control and Prevention, which would see their budgets cut by around half.

Democrats immediately rebuked Mr. Trump for his proposal. Senator Chuck Schumer of New York, the Senate minority leader, called it “heartless” and an “all-out assault on hardworking Americans.” Even some Republicans took issue with Mr. Trump’s budget, although others, like Speaker Mike Johnson, endorsed the blueprint.

Mr. Trump also asked Congress to reduce, if not eliminate, billions of dollars in federal aid to help the poorest Americans. For one, the White House called for reconfiguring federal programs that provide rental assistance to low-income families, cutting aid by more than $26 billion next fiscal year. And the administration proposed the termination of a federal initiative, backed by some Republicans, that aids needy families in paying their monthly heating bills.

In one of the few spending increases included in the budget, Mr. Trump asked lawmakers to bolster spending at the Department of Homeland Security by more than $43 billion, furthering his work to crack down on immigration, conduct deportations and build a wall along the U.S.-Mexican border. The president also requested more than $1 trillion for the military next fiscal year.

But he asked lawmakers to approve that increase essentially on a one-time basis, as part of a broader legislative package — due later this year — meant to advance the president’s tax agenda. The approach angered some Republicans, who signaled they would pursue a larger increase to military spending as part of the yearly process to fund government agencies and programs.

“It is peculiar how much time the president’s advisers spend talking about restoring peace through strength, given how apparently unwilling they’ve been to invest accordingly in the national defense or in other critical instruments of national power,” said Senator Mitch McConnell of Kentucky, the Republicans’ former Senate leader, in a statement that denounced the administration’s “accounting gimmicks.”

For Mr. Trump, the budget served to formalize his conservative vision and his disruptive reorganization of the government, a campaign that has already shuttered entire agencies and dismissed thousands of federal workers without the explicit approval of Congress.

Some of Mr. Trump’s proposed military increases could benefit Elon Musk, the tech billionaire who has advised Mr. Trump on cost-cutting as part of the Department of Government Efficiency

Mr. Trump’s budget supported the creation of a new missile defense shield and a renewed campaign for “U.S. space dominance.” Both are areas in which Mr. Musk and his rocket company, SpaceX, could stand to win major contracts funded by any increase in spending.

In a letter Friday accompanying the spending blueprint, Russell T. Vought, the leader of the White House budget office, said the administration had produced its submission after a “rigorous, line-by-line review of spending.”

Mr. Vought added that the president sought to root out money “contrary to the needs of ordinary working Americans and tilted toward funding niche, nongovernmental organizations and institutions of higher education committed to radical gender and climate ideologies antithetical to the American way of life.”

Sharon Parrott, the president of the left-leaning Center on Budget and Policy Priorities, said many of the budget changes contemplated by Mr. Trump still seemed most likely to fall hardest on low-income Americans, particularly those who rely on government services.

“This is the latest repudiation of some of what he promised on the campaign trail, in terms of being a president who was going to seek to serve people struggling at the margins of the economy,” she said.

Mr. Trump’s proposal is not law. Totaling about $1.7 trillion, after accounting for the full set of spending changes the president seeks, the budget serves only as a formal guide to Congress, where it immediately generated opposition.

“President Trump has made his priorities clear as day: He wants to outright defund programs that help working Americans while he shovels massive tax breaks at billionaires like himself and raises taxes on middle-class Americans with his reckless tariffs,” Senator Patty Murray of Washington, the leading Democrat on the Appropriations Committee, said in a statement.

The criticism was not limited to Democrats, as Republicans also raised alarm about cuts to some programs that serve the neediest Americans. Outlining her “serious objections,” Senator Susan Collins, a Maine Republican who leads the Appropriations Committee, added in a statement: “Ultimately, it is Congress that holds the power of the purse.”

By releasing the budget, Mr. Trump set the stage for what is bound to be a complicated, monthslong process to fund the government and avert a shutdown before an existing spending deal expires on Sept. 30. Entering that fight, many Republicans have echoed Mr. Trump’s desire to slash federal spending, though warring G.O.P. factions have disagreed at times over the exact scope.

Party lawmakers have also raced to identify potentially trillions of dollars in cuts that they can include to finance a related package that would expand a set of expiring tax cuts for families and businesses, one of the president’s signature — and costliest — economic policy priorities.

But Mr. Trump’s proposal carries additional significance. He and his top budget adviser, Mr. Vought, subscribe to the idea that the commander in chief wields expansive authority to halt or cancel spending, even if Congress instructs otherwise. Their view has paved the way for the administration to slow, freeze or cancel billions of dollars in funds, sparking a vast array of lawsuits and prompting more than three dozen ongoing federal investigations into their activities.

On Friday, Mr. Trump’s proposal left unanswered some of the most important questions facing Washington and its finances. It was silent on the nation’s fiscal trajectory, even as the president seeks to cut taxes in a sprawling and costly legislative package that carries substantial implications for the nation’s $36 trillion debt.

“It remains to be seen what the rest of the president’s proposals will hold, and there is still the multitrillion-dollar question of whether the reconciliation bill will blow up the debt,” said Maya MacGuineas, the president of the Committee for a Responsible Federal Budget, a group that advocates deficit reduction.

Nor did the president’s new budget address the future of the federal benefit programs, including Social Security, Medicare and Medicaid, that comprise the largest share of federal spending annually. Some Republicans are particularly interested in rethinking Medicaid, which provides health insurance to poor families, as a source of savings to pay for their tax cuts.

The administration is expected to send those details in a fuller budget to Congress as soon as this month.

Reporting was contributed by Alan Rappeport, Sheryl Gay Stolberg, Catie Edmondson, Eric Lipton, Devlin Barrett, Lisa Friedman, Brad Plumer, Madeleine Ngo and Alicia Parlapiano.