The US' defense budget, already the highest in the world, will be raised by 10 percent.
"The President is directing [OMB] Director Mulvaney to write a budget in accordance with which would be to fulfill all the promises from the campaign and to make this a security budget, increasing defense by $54 billion or 10% and having a corresponding reduction in non-defense spending by $54 billion," the official said.
The official explained that "most [agencies] will all see reductions with the exception of security agencies," including a "large reduction" in the foreign aid portion of the budget.
Foreign aid is making up less than one percent of US federal discretionary spending.
US presidential press secretary Sean Spicer also wrote about this on his Twitter account.
Earlier this month, Trump pledged to launch one of the "greatest military buildups in American history" by upgrading both defensive and offensive capabilities.
The United States is already NATO's top military spender, allocating over 3.6 percent of its GDP on defense in 2016.