The United States added 46,321 new coronavirus cases in 24 hours on Monday, according to a tally by Johns Hopkins University.
The world's largest economy also added 532 deaths, the Baltimore-based institution's tracker showed at 8.30pm (0030 GMT Tuesday).
By Tuesday morning European time the figures had risen further, the number of confirmed cases in the US increasing by over 2,000 to a total of 4,713,500, with 155,402 deaths, making it by far the worst-hit country in the world.
Monday was the second day to notch a slightly lower caseload, after a string of five days last week had all recorded more than 60,000 new daily infections.
President Donald Trump said during a coronavirus press briefing on Monday that the virus was "receding", deeming the situation "very encouraging."
"We're beginning to see evidence of significant progress," the US president told reporters. "Nationwide the number of positive cases has declined by nearly 6% from the week before, and the positive test rate has also dropped from 8.7 to 8% over the same period of time, an encouraging sign -- very encouraging, I have to add -- that the virus is receding."
"In hot spots across the South and West, we've seen slow improvements from their recent weekly peaks," Trump added.
But the day before, White House coronavirus adviser Deborah Birx had warned that the country was entering a "new phase" of the pandemic, with rural areas just as threatened as major cities.
"It is extraordinarily widespread," she told CNN on Sunday.
"To everybody who lives in a rural area, you are not immune or protected from this virus."
Trump did not answer a question as to whether he agreed with his adviser's assessment of outbreaks in the United States.
Earlier he criticised her in a tweet over her response to criticism from House Speaker Nancy Pelosi, saying that she "took the bait and hit us".
More than 18 million people worldwide have been infected with Covid-19 since the disease first appeared in China late last year. Around 680,000 have died.