Donald Trump at a rally with James Mattis, his pick for defense secretary. AP US President Donald Trump announced on Monday that his budget plan for fiscal year 2018 would include a historically-high $54 billion bump on defense spending ,while cutting a similar amount from the State Department and foreign aid — but his own Secretary of Defense James Mattis may not agree with that strategy.

The budget plan reflects Trump's often expressed desire to rebuild a military that he categorizes as "crumbling" and "depleted," but may go against wisdom expressed by Mattis, who said in 2013 that funding to the State Department prevents war.

“If you don’t fund the State Department fully, then I need to buy more ammunition ultimately," Mattis said, before members of Congress at a National Security Advisory Council meeting, the US Global Leadership Coalition notes.

"So I think it’s a cost-benefit ratio. The more that we put into the State Department’s diplomacy, hopefully the less we have to put into a military budget as we deal with the outcome of an apparent American withdrawal from the international scene,” Mattis continued.

In addition to the $54 billion Trump plans to request for 2018, administration sources said he will seek another $20 billion in supplementary military spending during fiscal year 2017, the Associated Press notes.

In 2016, the Department of Defense spent more than $516 billion, or about 14% of the budget on military programs, according to the US government.