According to newly-released recordings of interviews done in February for a book by journalist Bob Woodward, Trump acknowledged he knew how deadly and contagious the coronavirus was but played it down because he did not want to create a panic.

With weeks remaining until the November 3 presidential election, the news about Trump's comments on Wednesday again focused attention on the Republican president's efforts to battle COVID-19, which Democrats say have been too little, too late.

"He knew and purposefully played it down. Worse, he lied to the American people," Biden said, visiting the battleground state and home of the US auto industry, Michigan.

"And while this deadly disease ripped through our nation, he failed to do his job - on purpose. It was a life-and-death betrayal of the American people.

"It's a dereliction of duty, a disgrace."

Biden and Trump are ramping up travel in the final sprint to the election during a coronavirus pandemic that has made waging a traditional campaign all but impossible.

The president is expected to visit Michigan and Pennsylvania later in the week.

The United States has suffered the highest number of coronavirus deaths in the world.

Deaths topped 190,000 on Wednesday along with a spike in new cases in the Midwest and states like Iowa and South Dakota emerging as the new hot spots in the past few weeks.

Trump on Wednesday defended his handling of the virus, saying at the White House: "The fact is I'm a cheerleader for this country. I love our country and I don't want people to be frightened."

Biden also accused Trump of failing to fulfill his campaign vow, delivered in Michigan in the waning days of the 2016 race, to protect American jobs and prevent plants from closing.

Trump's victory in the state, by less than 11,000 votes, helped propel him to the presidency.

About a dozen United Auto Workers officials listened to Biden from folding chairs spaced for safety in the Detroit suburb of Warren in the crucial Republican-leaning Macomb County.

Biden, who has already proposed raising the corporate tax rate to 28 per cent from 21 per cent, said he would impose a 30.8 per cent rate on profits from products made overseas and sold in the United States.

His plan envisions a companion 10 per cent tax credit for companies that reopen closed facilities, bring jobs back to the United States or expand their manufacturing payroll.

While that would require congressional approval, Biden outlined several executive orders he would sign as president, unilateral measures ensuring government purchases primarily American-made goods.

"Make it in Michigan, make it in America, invest in our communities and our workers," he said.

Australian Associated Press