With many store shelves stripped bare of toilet paper, water and other essentials, the White House appealed to Americans on Sunday not to hoard as the coronavirus spreads, reassuring them that grocery supply chains were strong.
Panic buying has prompted Walmart and other stores to limit hours so they have time to restock and sanitize.
US President Donald Trump held a phone call on Sunday with 30 executives from grocery stores including Amazon.com Inc's Whole Foods, Target Corp, Costco Wholesale Corp and Walmart Inc, the White House said.
At the same time stores are overwhelmed, parents in many states are scrambling to care for children with schools closed.
Travelers returning to the United States and being screened for the coronavirus were met by long lines and massive delays at some major airports, prompting federal officials to deploy more staff and Trump to appeal for patience.
Trump said airport checks are "moving as quickly as possible but it is important to be vigilant and careful.
With limited testing available, US officials have recorded nearly 3,000 cases and 62 deaths. Globally more than 162,000 are infected and over 6,000 have died.
Trump tested negative for coronavirus, his doctors said on Saturday, as the president extended a travel ban to Britain and Ireland to try to slow the pandemic. The US House of Representatives passed an aid package on Saturday that would provide free testing and paid sick leave.
The US containment measures have so far been mild compared to the nationwide lockdowns imposed in Italy, France and Spain.
However, Ohio and Illinois on Sunday ordered all bars and restaurants to close, although carry-out and delivery are still allowed.
"I think Americans should be prepared that they are going to have to hunker down significantly more than we as a country are doing," Dr. Anthony Fauci, the nation's top infectious diseases expert, said on NBC's "Meet the Press." Elderly people and those with underlying conditions need to be especially cautious.
Fauci said he did not see domestic travel restrictions in the immediate future but warned, as he did last week, that the outbreak would get worse before it gets better.
Asked whether he thought US authorities should impose a 14-day lockdown to try to stop the spread of the virus, Fauci said: "You know, I would prefer (that) as much as we possibly could. I think we should really be overly aggressive and get criticized for over reacting."
Fauci said on CBS' "Face the Nation" the idea of closing restaurants in the United States "might be overkill right now, but everything is on the table." He said he himself would not go to a restaurant.
"If it looks like you're overreacting, you're probably doing the right thing," Fauci said.
Even though Americans are not barred from going to the movies, ticket sales in North America fell to their the lowest level for more than two decades this weekend, according to measurement firm Comscore.
HOSPITALS NEED MORE BEDS
Democratic New York State Governor Andrew Cuomo called on Trump, a Republican, to mobilize the Army Corps of Engineers to create more hospital beds.
"We have had disagreements about your actions against New York, which we can pursue at another time. Today, let's work together as Americans. Time is short," Cuomo wrote on Sunday in an opinion piece in the New York Times.
Cuomo has been criticized for not closing schools as other states have done, given that New York has a large cluster of coronavirus cases.
New York City Comptroller Scott Stringer called for a citywide shutdown. "We cannot go on with business as usual. This is about all of us. This is about protecting our most vulnerable," he said in a statement.
Speaking on ABC's "This Week" program, Fauci acknowledged that the 13,000 respirators that were in the US stockpile may not be enough if the number of cases in the United States jumped sharply. "What we're trying to do is make sure they don't get to the worst-case scenario."
He said that no hospital system in the world is prepared for a massive increase in coronavirus cases but the United States has taken steps.
"We have a stockpile and we will hopefully be able to backfill and refill that stockpile," he said. "But I think people should remember, that's the reason why we want to blunt that curve. If you let the curve get up there, then the entire society is going to be hit."