President Donald Trump has unveiled a $1.15 trillion budget, a far-reaching overhaul of federal government spending that slashes many domestic programmes to finance a significant increase in the military and make a down payment on a US-Mexico border wall.
Mr Trump's proposal seeks to upend Washington with cuts to long-promised campaign targets such as foreign aid and the Environmental Protection Agency, as well as strong congressional favourites such as medical research, help for homeless veterans and community development grants.
In a message accompanying his proposed budget, titled 'America First: A Budget Blueprint to Make America Great Again', he said:
"A budget that puts America first must make the safety of our people its number one priority - because without safety, there can be no prosperity."
The $54 billion (£43bn) boost for the military is the largest since President Ronald Reagan's Pentagon build-up in the 1980s, promising immediate money for troop readiness, the fight against Islamic State militants and procurement of new ships, fighter jets and other weapons.
The 10% Pentagon boost is financed by $54 billion in cuts to foreign aid and domestic agencies that had been protected by former president Barack Obama.
The budget goes after the frequent targets of the party's staunchest conservatives, eliminating the National Endowment for the Arts, legal aid for the poor, low-income heating assistance and the AmeriCorps national service programme established by former president Bill Clinton.
Such programmes were the focus of lengthy battles dating to the Republican takeover of Congress in 1995 and have survived prior attempts to eliminate them.
Politicians will have the final say on Mr Trump's proposal in the arduous budget process, and many of the cuts will be deemed dead on arrival.
White House budget director Mick Mulvaney acknowledged to reporters that passing the cuts could be an uphill struggle and said the administration would negotiate over replacement cuts.
Mr Mulvaney also went after Republican favourites, including aid to rural schools and health research, while eliminating subsidies for rural air service and the federal flood insurance programme that is a linchpin for the property market, especially in coastal southern states and the north-east.
Mr Trump's Republican allies on Capitol Hill gave it only grudging praise, if any.
House Appropriations Committee chairman Rodney Frelinghuysen reminded: "Congress has the power of the purse."
House Speaker Paul Ryan said: "I look forward to reviewing this", while Mr Mulvaney admitted "This is not a take-it-or-leave-it budget".
Law enforcement agencies such as the FBI would be spared, while the border wall would receive an immediate $1.4bn (£1.1bn) infusion in the ongoing fiscal year, with another $2.6bn (£2.1bn) planned for the 2018 budget year starting on October 1.
Mr Trump repeatedly claimed during the campaign that Mexico would pay for the wall when, in fact, US taxpayers will foot the bill.
The National Institutes of Health, meanwhile, would absorb a $5.8bn (£4.7bn) cut despite Mr Trump's talk in a recent address to Congress of finding "cures to the illnesses that have always plagued us".