President Trump has mocked his presidential rival Joe Biden for wearing a face mask so often and letting it hang off his ear when he gives speeches.
Speaking to his supporters - few of whom were wearing masks - at a campaign rally in Pennsylvania, Trump said: “Did you ever see a man who likes a mask as much as him?”
He added: "And then [when Biden] makes a speech and he always - not always, but a lot of times - he has it hanging down because, you know what, it gives him a feeling of security.
"If I were a psychiatrist I'd say: 'This guy’s got some big issues.'"
Trump has worn a mask in public on only a handful of occasions. He has said there is a "time and a place" for wearing a mask, but was criticised earlier this year when he failed to back scientific guidance recommending the wearing of them to help stop the spread of the virus.