Speaking at a rally in Carson City, Nevada, Trump imitated the former vice president, saying he would "listen to the scientists."
"If I listened totally to the scientists, we would right now have a country that would be in a massive depression," Trump said. "We're like a rocket ship."
He then attacked the Democratic governors of several states who have put in place measures to stop a likely second wave of Covid-19.
"Get the places open, let's go," he said.
A spokesman for Biden's campaign, Andrew Bates, swiftly responded to Trump in a tweet.
"This is tellingly out of touch and the polar opposite of reality," Bates said. "Trump crashed the strong economy he inherited from the Obama-Biden Administration by lying about and attacking the science, and layoffs are rising. Meanwhile, Joe Biden would create millions more jobs than Trump."
At a campaign stop earlier Sunday in Durham, North Carolina, Biden highlighted rising Covid-19 case counts, which reached their highest single-day total since late July on Friday, before pointing to recent remarks Trump has made downplaying the virus.
"Yet, the other night, Trump said in one of his rallies, 'we've turned the corner,'" Biden said. "As my grandfather would say, this guy's gone around the bend if he thinks we've turned the corner. Turn the corner? Things are getting worse. He continues to lie to us about the circumstances."
Referring to Trump's remarks telling the journalist Bob Woodward that he had downplayed the severity of the virus so people would not panic, Biden said, "The American people do not panic — Trump panicked."
The drive-in rally featured attendees chanting and honking from their cars. A rallygoer shouted: "Send him home, Joe."
Trump has in recent days said repeatedly that the country is "rounding the corner" when it comes to the pandemic.
"We are rounding the corner and we have — unbelievable," Trump said Saturday at a rally in Janesville, Wisconsin. "The vaccines are unbelievable. Except for a little politics. We have unbelievable vaccines coming out real soon. And the therapeutics are unbelievable."
The president has talked up the available therapeutics for Covid-19 after he contracted the virus and was treated this month with an antibody cocktail, remdesivir, and a heavy steroid typically associated with more severe cases.
Covid-19 case numbers are on the rise nationwide, with hospitalizations beginning to tick up, as well. Deaths have trailed off since early August, but they tend to be a lagging indicator of a pandemic's severity.
So far, more than 220,000 people in the U.S. have died of Covid-19, according to an NBC News tracker.