Early Sunday, the nationwide death toll had gone up to at least 8,503 people, with at least 312,245 infected, according to data compiled by Johns Hopkins University.
The U.S. surgeon general offered some of the starkest warnings yet Sunday as he braced Americans for the worsening fallout from the new coronavirus, warning "this is going to be the hardest and the saddest week of most Americans' lives, quite frankly".
"As hard as this week is going to be, there is a light at the end of the tunnel if everyone does their part for the next 30 days", Adams said.
On Saturday (local time), Dr Deborah Birx, coordinator of the White House Coronavirus Task Force, said she expected death tolls to rise quickly in the coming week.
"But that's what is going to happen before it turns around, so just buckle down", Fauci said on CBS's "Face the Nation".
The governor said rapid testing, still out-of-reach, was key to a "return to normalcy", while reiterating appeals for equipment including ventilators from other states as well as from the federal stockpile.
In doing so, they've collectively ignored the stay-at-home pleas of Dr. Anthony Fauci, the nation's top infectious disease expert, who said in a CNN interview: "If you look at what's going on in this country, I just don't understand why we're not doing that".
He emphasized the need to stay home this week in particular, to protect themselves and others.
"There will be a lot of death, unfortunately". NY state leads the nation in cases, although the death rate may actually be higher in New Orleans, according to some experts.
Her warning came as the state of NY reported its first fall in coronavirus deaths on Sunday, with 594 fatalities compared with 630 on Saturday.
"We have a thing called the Constitution, which I cherish", Trump said Saturday, praising the decision of the governors.
While most states have adopted restrictions on people's movement, a few states have declined to order residents to stay home.
Fauci also warned that unless the world gets the virus under control, it will "assume a seasonal nature".
He said those nine states where a stay-at-home order hasn't been issued "actually produce a large amount of our food" and are balancing the need to "provide for the rest of the country" with the need to avoid spreading the virus. "But if you can't give us 30 days, governors, give us, give us a week, give us what you can, so that we don't overwhelm our health care systems over this next week".