US President Donald Trump has signed an $8.3bn (£6.4bn) emergency bill to combat the coronavirus outbreak.
With confirmed US cases reaching 233 – in addition to 14 deaths – Mr Trump urged calm, adding: “It’ll go away.”
The White House has faced criticism for its response, and has acknowledged the US does not have enough test kits to meet rising demand.
Results are being awaited of tests on passengers on board a cruise ship being held off San Francisco, California.
Dozens of passengers were tested on Thursday after a passenger died and at least four others became infected on a previous voyage by the ship, the Grand Princess.
More than 100,000 coronavirus cases have been confirmed worldwide and over 3,400 deaths, according to data collated by Johns Hopkins University. The majority of cases and deaths are in China, where the virus first emerged in December.
Stocks in Asia and the UK fell sharply on Friday as investors continued to worry about the broader economic effects of the virus.
What’s the latest across the US?
Infections have been reported in 22 states throughout the country.
Thirteen of the 14 US fatalities were from the same nursing home in Seattle, Washington State.
City officials have recommended that Seattle residents aged 60 or older remain in their homes and cancel events with more than 10 people.
On Friday, the University of Washington said it would cancel classes for its 50,000 students – moving teaching online, instead – for the remainder of the winter term, which ends on 20 March.
The majority of US patients remain concentrated on the West Coast – combined, Washington state and California account for 141 of the 233 cases – but infections are now spreading across the country.
In New York, the number of confirmed cases jumped from 22 to 33 in just one day. Governor Andrew Cuomo said that there were 4,000 people under “precautionary quarantines”. They were people who have recently returned from places where the outbreak is most severe, including China, Italy, Iran, South Korea and Japan, but do not have any symptoms.