Two more people succumbed to the novel coronavirus in Washington state, officials said on Saturday, bringing the nationwide total to 19, while the number of confirmed cases in New York rose to 89 and a cruise ship with infected passengers remained stranded outside San Francisco.
More than half of all US states have reported cases of the coronavirus, which originated in China last year and causes the sometimes deadly respiratory illness COVID-19.
As the outbreak takes root, daily life has become increasingly disrupted, with concerts and conferences canceled and universities telling students to stay home and take classes online.
Organizers of the Conservative Political Action Conference, a high-profile annual gathering that took place in Maryland last month, said on Saturday one of their attendees had tested positive for the virus after exposure prior to the event.
The person had no interactions with President Donald Trump or Vice President Mike Pence, who were in attendance, the American Conservative Union said in a statement.
The two latest deaths were in Washington's King County, the hardest hit area in the United States after the virus spread among residents at a nursing facility in the Seattle suburb of Kirkland
The first deaths on the East Coast were announced late Friday, with two people succumbing in Florida.
In New York, the number of confirmed cases rose by 13 on Saturday to a statewide total of 89 people, Governor Andrew Cuomo said.
He issued a declaration of emergency."It allows expedited purchasing and expedited hiring, which is what we need right now," Mr Cuomo told a news conference.
Kansas, Missouri and Washington DC announced their first cases.
In international waters off California, passengers on a cruise ship that was barred from docking in San Francisco after some aboard tested positive for the novel coronavirus did not know on Saturday when they might be able to step ashore.
Trump said on Friday he would prefer the Grand Princess's 2,400 passengers and 1,100 crew remain out at sea, but that he would let others decide where she should dock.
After 19 crew and two passengers out of 46 tested on the Grand Princess were found to have the virus, Pence said the ocean liner will be taken to an unspecified non-commercial port where everyone on board will be tested again, and that those "who need to be quarantined will be quarantined" and those who need medical care will receive it.
US officials also began tracking another cruise ship that may have shared crew with the Grand Princess or the Diamond Princess, another ship where the coronavirus spread onboard, Mr Pence said.
One Grand Princess passenger described a dull and sometimes queasy wait for news of when their limbo would end.
"It bugs me that my relatives in the Bay Area know what's going to happen with us before I do," Elizabeth Aleteanu of Colorado Springs said in an interview conducted via Facebook.
She turned 35 on Wednesday in a small, windowless cabin shared with her husband and two young
children, where the rocking of the vessel sometimes left her nauseated.
"The cruise director and staff called my phone and sang happy birthday," she wrote.
"They delivered a princess notebook, birthday card, set of dominoes and a flower arrangement to my cabin. I'm not sure that we're getting off today. It's a big flower arrangement ..makes me think we'll be on board for a hot minute."
The ship's captain had addressed passengers earlier to say he did not know when they could dock, and that one guest who was critically ill on Friday was taken off the ship, Elizabeth Aleteanu said.
The ship has increased its offering of television programs to help passengers pass the time, she said.
The predicament of the Grand Princess was reminiscent of the Diamond Princess cruise liner, also owned by Carnival Corp, the world's leading cruise operator.
It was quarantined off Japan in February and was for a time the largest concentration of coronavirus cases outside China.
Stephen Hahn, the commissioner of the US Food and Drug Administration, told a news conference at the White House on Saturday that a total of 2.1 million coronavirus tests will have been shipped to non-public labs by Monday, as the Trump administration aims to counter criticism that its response to the disease has been sluggish.
Mr Hahn said the focus is on getting tests to the highest risk areas in Washington state and California. Multiple manufacturers will soon send millions more tests, he said.
"What they told us is they believe they could scale up by the end of next week ..for the capacity for 4 million additional tests that could be shipped," Mr Hahn said.
The respiratory illness has spread to more than 90 countries, killing more than 3,400 people and infecting more than 100,000 worldwide.
The economic damage has also intensified and stock markets have continued to tumble.
To mitigate against the virus, some banks in New York are dividing their teams of traders between central locations and secondary sites in New Jersey and Connecticut, according to sources familiar with the matter.
Goldman Sachs Group Inc had a scare this past week when an employee at its Lower Manhattan offices told the bank he had been at a temple service in a city suburb with a lawyer who later tested positive for the coronavirus.
The bank said the employee was sent home and has been under self-quarantine since then "out of an abundance of caution." The employee, however, did not have contact with the lawyer at the service and has not shown any signs of illness, the bank said.
He is expected to return to work next week when it would have been two weeks since he attended the service.
Goldman also cleaned the floor on which he worked at its headquarters.
All floors remained operational, though Goldman let employees who felt uncomfortable work remotely, it said."We have no confirmed cases of employees who have contracted COVID-19 and all our buildings are fully operational," the bank said.