US president Donald Trump informed the media on Tuesday that Americans must "be prepared for the hard days that lie ahead", as the death toll stateside went beyond 4,000.
Trump stopped short of telling the press the number of US citizens projected to be killed by Covid-19 amid new social distancing measures, saying that he would leave that to the medical experts.
According to reports, there are fears that between 100,000 to 200,000 Americans could still die.
It is estimated that April 15 will be one of the deadliest days, with 2,214 US nationals expected to be lost.
Trump added: "This is going to be a very, very painful two weeks.
"A lot of people were saying think of it as the flu, but it's not the flu. It's vicious".
Trump's latest comments represent a real U-turn for the president, who in previous weeks has compared the coronavirus outbreak to the threat of the flu himself.
During a briefing last week, Trump said: "We lost thousands of people a year to the flu. We never turn the country off".
Director of the US National Institute of Allergy and Infectious Diseases, Dr Anthony Fauci, said on Tuesday: "No-one is denying that we're going through a very, very difficult time. That's what it is".
Once again, the wider message from the White House was to urge Americans to adhere to social distancing measures to help curb the spread of the virus.
Dr Deborah Birx, one of the members of the Coronavirus Task Force said: "There's no magic bullet. There's no magic vaccine or therapy. Just behaviours".
Social distancing regulations in the US have been extended until April 30.