US President Donald Trump's first budget proposal will reportedly cut funding for the State Department and the Environmental Protection Agency (EPA) by as much as 30%, according to staff familiar with the plan.
The budget plan for the 2018 fiscal year will look to make the cuts while increasing military spending by $54bn (£44bn), as was announced in February.
It will also look to make big savings in the State Department's Food for Peace programme, which sends aid to countries devastated by war or natural disaster, and from a Transportation Department programme that subsidises flights to rural US airports.
Members of Congress, who must approve any budget proposals, briefed reporters from the New York Times about the cuts, before they are made public at 7am EST (12pm GMT) on Thursday (16 March).
The budget will initiate months of heated debates about government spending, with Democrats and moderate Republicans fighting to protect popular programmes and Conservatives pushing for more cuts and "smaller government".
During the 2016 presidential race, Trump promised huge hikes in infrastructure spending, which means that further cuts are likely to balance the equation.
Senior Republicans oppose cuts
Prominent Republicans, who traditionally argue for smaller budgets, have already indicated they will not back Trump's cuts to the State Department and United States Agency for International Development. Senate Majority Leader Mitch McConnell of Kentucky is reportedly among them.
Senator Lindsey Graham, a Republican from South Carolina, told New York Times reporters: "This [budget] is definitely dead on arrival."
In spite of the opposition, Trump is also expected to propose cuts to public education, the Department of Housing and Urban Development and to transportation programmes like Amtrak.
Social programmes such as Social Security and Medicare account for the majority of America's federal government costs. However, Trump pledged to protect those two areas during his election campaign.