(Bastien Inzaurralde/The Washington Post)

President Trump will propose a federal budget that would significantly increase defense-related spending by $54 billion while cutting other federal agencies by the same amount, an administration official said.

The proposal represents a major increase in federal spending related to national security, while other priorities, especially foreign aid, would face massive reductions.

According to the White House, the defense budget would increase by 10 percent. Trump also will request $30 billion in supplementary military spending for fiscal 2017, an administration official said.

But without providing specifics, the administration said that most other discretionary spending programs would be cut to pay for it. Officials singled out foreign aid, one of the smallest parts of the federal budget, saying it would face “large reductions” in spending.

It is the first indication of spending priorities by the new administration, with the president set to arrive on Capitol Hill on Tuesday night for a speech to a joint session of Congress. But the full budget negotiations between Trump and Congress will not be complete for many months.

In a statement at the White House on Monday morning, Trump said that his budget would put “America first” by focusing on defense, law enforcement and veterans using money previously spent abroad.

“We are going to do more with less and make the government lean and accountable to the people,” he said. “We can do so much more with the money we spend.”

The White House did not specify how Trump’s budget would address mandatory spending or taxes, promising that those details would come later. The vast majority of federal spending comes from programs Trump can’t touch with his budget. Social Security costs totaled about $910 billion last year, and Medicare outpaced defense spending with a total cost of $588 billion. Medicaid, interest payments on debt and miscellaneous costs made up an additional $1.2 trillion.

White House officials declined to answer questions about the president’s priorities on a host of other fiscal issues, including infrastructure improvements and plans to pay for a wall between the United States and Mexico. Mick Mulvaney, director of the Office of Management and Budget (OMB), emphasized that the priorities outlined Monday do not reflect policy on broader fiscal issues, which he said will be addressed later.

“We are taking his words and turning them into policies and dollars,” Mulvaney told reporters. “A full budget will contain the entire spectrum of what the president has proposed.”

Defense spending accounts for almost the same proportion of the federal budget as all non-discretionary domestic spending, meaning that the Trump administration’s proposal will result in a roughly 10 percent across-the-board cut in all other federal spending programs.

Budgets for most federal agencies would be reduced substantially, said an OMB official, who spoke on the condition of anonymity on a call with reporters to discuss the proposal.

The announcement marks the beginning of a process in which the OMB will coordinate with agencies to flesh out the plan.

Trump said his budget, which will be submitted to Congress next month, will propose “historic” increases in spending to bolster the country’s “depleted military,” and he said it will support law enforcement in an effort to reduce crime.

Trump noted that the country faces an urgent infrastructure problem, which he promised during the campaign that he would address with a $1 trillion infrastructure spending plan. Although the administration has not yet outlined whether infrastructure will be part of Trump’s budget proposal, the president spoke about it at length before a gathering of governors at the White House on Monday.

“We’re going to make it easier for states to invest in infrastructure,” he said. “We spent $6 trillion in the Middle East, and we have potholes all over our highways and our roads.”

He added: “Infrastructure, we’re going to start spending on infrastructure — big.”

Republicans in Congress expect that the details released this week will be the first elements of a broader budget that will be rolled out next month. The Trump administration is expected to release a pared-down “skinny budget” the week of March 13 and a fuller list of requests by the end of March or early April, said multiple Republican congressional aides who spoke on the condition of anonymity to discuss the process.

Democrats have warned that under the current circumstances, Trump would be hard-pressed to make significant cuts to domestic programs without significantly reducing some government services. Senate Minority Leader Charles E. Schumer (D-N.Y.) said Monday that the scant details the Trump administration released probably would lead to cuts to widely used programs.

“A cut this steep almost certainly means cuts to agencies that protect consumers from Wall Street excess and protect clean air and water,” Schumer said.

House Minority Leader Nancy Pelosi (D-Calif.) added that deep reductions could have a major effect on programs that keep the American workforce competitive.

“A $54 billion cut will do far-reaching and long-lasting damage to our ability to meet the needs of the American people and win the jobs of the future,” she said in a statement. “The President is surrendering America’s leadership in innovation, education, science and clean energy.”

Individual agencies were expected to begin the customary process of sending budget requests for the upcoming fiscal year to the White House beginning Monday, the aides said. The OMB will then begin drafting an official request for fiscal 2018 and submit it to Congress in the coming weeks.

Congress typically does not agree with the White House budget in full, even when the president and congressional leaders represent the same party. Republican leaders have not yet said when they will release their budget blueprint for the fiscal year that starts Oct. 1.

House Speaker Paul D. Ryan (Wis.) told members at a GOP retreat in Philadelphia in January that he expects to act by July on a 2018 budget proposal that will lay out major spending cuts and begin the process of rewriting the tax code.

Philip Rucker and Ana Swanson contributed to this report.