US President Donald Trump is seeking a "historic increase" in military spending to be funded by cuts elsewhere in government.
Mr Trump will seek to boost Pentagon spending by US$54 billion (NZ$74.8b) in his first budget proposal - and slash the same amount from non-defence spending, including a large reduction in foreign aid, a White House budget official said on Tuesday.
"This budget will be a public safety and national security budget," Trump told state governors at the White House.
"It will include an historic increase in defence spending to rebuild the depleted military of the United States of America at a time we most need it," he said.
The US military is already the world's most powerful fighting force and the United States spends far more than any other country on defence.
The White House will send Mr Trump's proposal to federal departments on Monday as he gears up for budget negotiations with Congress that often take months to play out.
Congress, controlled by Mr Trump's fellow Republicans, has the final say on federal spending.
In a speech to conservative activists on Friday, Mr Trump promised "one of the greatest military buildups in American history".
Two officials familiar with Mr Trump's proposal said the planned defence spending increase would be financed partly by cuts to the State Department, Environmental Protection Agency and other non-defence programs.
One of the officials said Mr Trump's request for the Pentagon included more money for shipbuilding, military aircraft and establishing "a more robust presence in key international waterways and choke points" such as the Strait of Hormuz and South China Sea.
A second official said the State Department's budget could be cut by as much as 30 per cent, which would force a major restructuring of the department and elimination of programs.
Some defence experts have questioned the need for a large increase in US military spending, which already stands at roughly $US600 billion annually.
By contrast, the United States spends about $US50 billion annually on the State Department and foreign assistance.