Donald Trump has instructed close advisers to play down internal White House polling that showed him losing heavily to Joe Biden in key industrial "rust belt" states ahead of the 2020 election.

According to a leaked 17-state poll, conducted by the president's pollster Tony Fabrizio, Mr Trump was down 16 points in Pennsylvania, and 10 points in Wisconsin, both of which he won narrowly in 2016.

Mr Trump was also trailing Mr Biden by seven points in Florida, which he won in 2016, and was only two points ahead in the traditionally Republican state of Texas.

As Washington was gripped by its first bout of 2020 poll fever White House officials said their own initial research no longer carried any weight.

In a statement Brad Parscale, Mr Trump's campaign manager, said the polling was "ancient," having been conducted in March.