In his first budget, the US president is also looking to slash funding to the arts, science, foreign aid and environmental protection. UN warns that more is needed to fight terror than just military spending.
President Donald Trump will ask the US Congress for dramatic cuts to many federal programmes as he seeks to bulk up defence spending, start building a wall on the border with Mexico and spend more money deporting illegal immigrants.
In a federal budget proposal with many losers, the Environmental Protection Agency and State Department stand out as targets for the biggest spending reductions.
Funding would disappear altogether for 19 independent bodies that count on federal money for public broadcasting, the arts and regional issues from Alaska to Appalachia.
Trump's budget outline is a bare-bones plan covering just "discretionary" spending for the 2018 fiscal year starting on October 1.
It is the first volley in what is expected to be an intense battle over spending in coming months in Congress, which holds the federal purse strings and rarely approves presidential budget plans as drafted.
Congress, controlled by Trump's fellow Republicans, may reject some or many of his proposed cuts.
Some of the proposed changes, which Democrats will broadly oppose, have been targeted for decades by conservative Republicans.
In addition to the fiscal year 2018 request, a copy of a supplemental budget for fiscal year 2017 shows the administration plans to ask for $30 billion for the Department of Defense and $3 billion for the Department of Homeland Security.
The funds would be allocated this year to cover procurement of military technology such as F-35 fighter aircraft and drone systems, begin construction on the US-Mexico border wall and increase detention space for migrants. Congress likely will consider the supplemental request by April 28, when the current regular funding expires.
Moderate Republicans already have expressed unease with potential cuts to popular domestic programs such as home-heating subsidies, clean-water projects and job training.
UN says more needed to combat terror
The UN warned on Thursday that "more than military spending" is needed to combat terrorism, after US President Donald Trump proposed an extra $54 billion in military spending in 2018.
"There is also a need to address the underlying drivers of terrorism through continuing investments in conflict prevention, conflict resolution, countering violent extremism, ….. the enhancement and respect of human rights, and timely responses to humanitarian crises," Antonio Guterres' spokesman Stephane Dujarric said.
The world body further warned that its operations could suffer if the US were to slash funding to the UN as called for in Trump's first budget proposal.
Open for discussion
Trump is willing to discuss priorities, said White House budget director Mick Mulvaney, a former South Carolina congressman who made a name for himself as a spending hawk before Trump plucked him for his Cabinet.
"The president wants to spend more money on defence, more money securing the border, more money enforcing the laws, and more money on school choice, without adding to the deficit," Mulvaney told reporters during a budget preview on Wednesday.
"If they have a different way to accomplish that, we are more than interested in talking to them," Mulvaney said.
Democrats criticised the proposed budget as lacking in detail and said it would be devastating to American families.
"President Trump is not making anyone more secure with a budget that hollows out our economy and endangers working families," said House of Representatives Democratic leader Nancy Pelosi. "Throwing billions at defence while ransacking America's investments in jobs, education, clean energy and lifesaving medical research will leave our nation weakened."
Trump wants to spend $54 billion more on defence, put a down payment on his border wall, and breathe life into a few other campaign promises.
His initial budget outline does not incorporate his promise to pour $1 trillion into roads, bridges, airports and other infrastructure projects.
The White House has said the infrastructure plan is still to come.
The defence increases are matched by cuts to other programmes so as to not increase the $488 billion federal deficit.
Mulvaney acknowledged the proposal would likely result in significant cuts to the federal workforce.
"You can't drain the swamp and leave all the people in it," Mulvaney said.
The Department of Homeland Security would get a 6.8 percent increase, with more money for extra staff needed to catch, detain and deport illegal immigrants.