President Donald Trump is unveiling a $1.15tr (£937bn) budget today (16 March) that makes deep cuts to dozens of social services, the arts, and sciences to pay for his US-Mexico border wall and $54bn military buildup.

"If [Trump] said it on the campaign, it's in the budget," said Mick Mulvaney, Director of the US executive branch Office of Management and Budget, in a press briefing on yesterday. "This is the 'America First' budget. In fact, we wrote it using the president's own words," he said.

Mulvaney said his team spoke with the president and went back through his speeches "and we turned those policies into numbers".

Titled America First: A Budget Blueprint to Make America Great Again, it eliminates legal aid for the poor and low-income heating assistance, along with the National Endowment for the Arts, the National Endowment for the Humanities, and the Corporation for Public Broadcasting, which largely funds PBS and National Public Radio.

It also does away with former President Barack Obama's Clean Power Plan to tighten regulations on climate change contributing carbon emissions from power plants. And it eliminates $5.8bn from the National Institutes of Health, which carries out biomedical and health research. Within the Environmental Protection Agency 50 programmes and 3,200 civil service positions face the chopping block.

The US's State Department which handles foreign diplomacy around the world can expect a 28% cut, Mulvaney said.

In all, 12 of the government's 15 Cabinet agencies face deep cuts. What's cut from them will go to the military to foot Trump's $54bn defence buildup. Trump's US-Mexico border wall project will also immediately receive $1.5bn in funding for this year with $2.6 billion lined up for 2018 starting on 1 October.

"There's more money for enforcing laws on the books just generally. Then there's more money for things like private and public school choice," said Mulvaney.

The cuts and spending will not pay down any of the roughly $488 billion budget deficit the US will see in 2018.

"A budget that puts America first must make the safety of our people its number one priority," Trump said in a statement accompanying the budget. "Without safety, there can be no prosperity."

US President Donald Trump is unveiling his America First budget today Reuters/Jonathan Ernst