New Hampshire, Georgia and North Carolina were the most recent to have joined the list of states with first confirmed cases reported.
All nine deaths occurred in the Seattle area of Washington state. A long-term care facility in the state's Kirkland city is considered to be the site of an outbreak, as a growing number of confirmed cases are from there.
In New York state, a man from the Westchester County just outside of New York City was diagnosed with COVID-19, bringing the state's confirmed cases to two, local authorities said Tuesday.
The patient, a 50-year-old man who works in Manhattan, is currently hospitalized and in serious condition.
The man has not traveled to any countries or regions at the nexus of the COVID-19 outbreak. Authorities are trying to find out how he got infected and who might have been infected because of him.
At least two schools in New York City and surrounding areas were closed on Tuesday due to the second confirmed case.
To quell fear and panic, New York State Governor Andrew Cuomo stressed that 80 percent of those infected will recover by themselves. "They may not even know they had the virus. It would be like a flu with mild symptoms," he said.
Meanwhile, he acknowledged that there would be a continuing spread, which demonstrates the importance of strengthening capacity for testing. The state health department will share its testing protocol with private laboratories to increase the capacity, he added.
Due to concerns over a further spread of the virus, several major events scheduled for March in the country have been removed from the calendar.
In the island state of Hawaii, a premier cultural event, the 26th annual Honolulu Festival, has been canceled.
The Honolulu Festival Foundation announced in a statement on Tuesday that the move is in response to recommendations made by government health officials.
The three-day event was expected to draw thousands of visitors from throughout the region, including more than 100 groups who would share their culture through music, dance and arts in free performances.
In Chicago, the Inspired Home Show, which was scheduled for March 14-17 and expected to attract around 2,200 exhibitors and some 52,000 visitors, has been canceled by the event's organizer.
Meanwhile, a person suspected of being infected with COVID-19 is being treated at the University of Chicago Medical Center and awaiting lab tests, the hospital said Tuesday.