The U.S. Senate is due to begin voting late on Tuesday on President Donald Trump's request to slash billions in spending on foreign aid and public broadcasting previously approved by Congress, the latest test of Trump's control over his fellow Republicans.

The Senate has until Friday to act on the rescissions package - a request to claw back $8.3 billion in foreign aid funding and $1.1 billion for public broadcasting - or the request will expire and the White House will be required to adhere to the spending plans passed by Congress.