Under-fire Trump announces new campaign manager

United States President Donald Trump has announced a new head of his re-election campaign -- less than 16 weeks ahead of the November 3 presidential election.

"I am pleased to announce that Bill Stepien has been promoted to the role of Trump Campaign Manager," the president said in a Facebook post on Wednesday night.

Stepien, Trump's former second-in-command, replaces Brad Parscale as the president's campaign manager.

Stepien has previously worked for former New Jersey governor Chris Christie and has served as Trump's national field director in 2016.

"Brad Parscale, who has been with me for a very long time and has led our tremendous digital and data strategies, will remain in that role, while being a Senior Advisor to the campaign," Trump said.

"Both were heavily involved in our historic 2016 win, and I look forward to having a big and very important second win together," he added.

"This one should be a lot easier as our poll numbers are rising fast, the economy is getting better, vaccines and therapeutics will soon be on the way, and Americans want safe streets and communities!" Trump said.

Latest opinion polls show that Trump's Democratic rival Joe Biden is leading the national polls by more than eight percentage points.

Parscale ran Trump's digital advertising in the 2016 US presidential polls and was credited with helping bring about the Republican candidate's surprise victory.