US President Donald Trump has signed an $8.3bn (£6.4bn) emergency bill to combat the coronavirus outbreak.
With confirmed cases reaching 233 ,in addition to 14 deaths , 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.