COVID-19 has been the No. 1 issue in the presidential election, with President Donald Trump telling campaign rallies that the US has "rounded the turn'' on the pandemic, but a top White House adviser on the coronavirus has broken ranks with Trump.

Dr Deborah Birx, coordinator of the White House task force on the virus, has called for "an aggressive balanced approach that is not being implemented" and warned that the pandemic could be about to enter a "deadly phase" with 100,000 infections a day.

Birx said in an internal report for White House officials that was obtained by The Washington Post on the eve of the presidential election: "We are entering the most concerning and most deadly phase of the pandemic ... leading to increasing mortality,

"This is not about lockdowns; it hasn't been about lockdowns since March or April. It's about an aggressive balanced approach that is not being implemented."

She also says in the report: "Cases are rapidly rising in nearly 30 percent of all USA counties, the highest number of county hotspots we have seen with this pandemic. Half of the United States is in the red or orange zone for cases despite flat or declining testing."

More than 9.3 million people have been infected with coronavirus in the US, and 232,000 have died.

Trump has praised his "phenomenal job" of handling the coronavirus pandemic. And Democratic rival Joe Biden has repeatedly played up Trump's "mishandling" of the virus as he crisscrossed the country on campaign stops.

The US had 84,000 new coronavirus cases on Monday. It was 73,594 on Sunday. On Friday, the US set an all-time record high of 99,321 cases — the highest single-day figure in the world — according to Johns Hopkins University.

The national seven-day average was 83,805 as of Monday. And the number of people hospitalized with COVID-19 has also risen to its highest number since Aug 9 — with 48,470 — data from the Covid Tracking Project showed. Pennsylvania, Kansas, Connecticut and Rhode Island have had some of the highest daily infection rates.

Trump has repeatedly complained that the media is too focused on "Covid! Covid, Covid, Covid'' and predicted that it would end on Nov 4.

When Trump supporters at a rally late Monday night in Florida chanted "Fire Fauci!", Trump suggested that he would consider firing Dr Anthony Fauci, a member of the White House Coronavirus Task Force and director of the National Institute of Allergy and Infectious diseases since 1984. "Don't tell anybody but let me wait till a little bit after the election," Trump responded to the chant.

On Monday night, Biden said at a rally in Cleveland: "Trump said he was going to fire Dr Fauci. Isn't that wonderful? I got a better idea. Elect me, and I'm going to hire Dr Fauci, and we're going to fire Donald Trump."

Fauci stoked Trump's anger after saying last week that there could be a record surge in coronavirus cases and hospitalizations this winter. "We're in for a whole lot of hurt," he told the Post.

Scott Gottlieb, former commissioner of the Food and Drug Administration, on Tuesday warned that the US soon could have 1,000 people dying a day for a "sustained period of time". And he echoed Birx by saying that there could be 100,000 infections a day in the next couple of weeks.