And Trump sought to recapture the spirit of his shock win four years ago by casting himself as the rebel against an "arrogant, corrupt, ruthless" establishment.
Biden, the 77-year-old former vice president, has enjoyed a solid lead over Trump, 74, in the national polls for months, at times reaching double digits.
Fauci said Biden was "taking it seriously from a public health perspective", while Trump was "looking at it from a different perspective… the economy and reopening the country".
For the first time since the start of the campaign, Biden will be joined on stage in Michigan by his former boss and most popular campaigner Barack Obama.
He said that in Germany and other countries, when a person who dies from cancer or any other terminally ill disease, he is said to have died from that same disease. However, when it comes to doctors in the US, they lie and say the patient died of the coronavirus.
Huge numbers of people have voted by mail or at early in-person polling sites amid concerns the coronavirus could spread at busy Election Day voting places.
According to the tally from the US Elections Project, it which shows a record-breaking pace that could lead to the highest voter turnout in percentage terms in mote then a century.
Such was the popularity of the Trump figure in the run-up to the 2016 elections that Alos felt certain he would take the White House, despite polls pointing to a Hillary Clinton victory.
"It might not be finished by Election Day. It may be finished by Election Day. But I'd want it by next Friday," Pelosi said. "Nov. 1, rent day. Let's see if we can't do that."
The Trump campaign, with 2.2 million followers, said in a new tweet it was "re-posting the video Twitter doesn't want you to watch.
It's going to all end up in a big lawsuit and there are things that can happen that are very severe that I'd rather not see happen, but it's probably going to have to,