White House communications director Bill Shine has resigned as President Donald Trump's top White House communications aide and will move to work on the U.S. leader's 2020 re-election campaign, the White House said on Friday.

Shine, a former Fox News executive, resigned on Thursday and will serve as a senior campaign adviser ahead of the 2020 presidential election, White House spokeswoman Sarah Sanders said in a statement.

A source close to Trump, speaking on condition of anonymity, said the president had lost confidence in Shine and was relying heavily on Sanders to run the communications operation.