New York City and Los Angeles have shut down bars, restaurants and other public places.
Casinos and hotels in Las Vegas have also closed as the US tries to stop the spread of coronavirus.
Meanwhile, another 368 people have died in Italy, its largest number of fatalities in a day since the outbreak started.
Over 1,800 deaths have now been recorded in the country.
John Murphy from Dublin is on lockdown in Puglia - and says people are trying to stay positive:
"The government has been very good at it making it very clear what we're doing and why we're doing it - everyone accepts it.
"Morale is pretty good - everyone is concerned that the numbers are still rising and they haven't flattened out yet, but we know it's going to get better soon
We're just waiting for that to happen."
