Donald Trump's defence secretary has distanced himself from the president's war on media, calling journalists a constituency of the democratic process.

James Mattis' comments came after his commander-in-chief declared the fifth estate the "enemy of the American people" and vowed to "expose them for what they are".

"The press, as far as I'm concerned, are a constituency that we deal with," Mr Mattis said. "And I don't have any issues with the press, myself."

Mr Trump often mocked the "dishonest" media in his presidential campaign. But since taking office, this denigration has morphed from crowd pleasing rhetoric into a strategy seemingly intended to discredit journalists reporting unflattering revelations of dysfunction and divisions in his White House.