New York City is closing schools on Monday, and restaurants, bars and other venues a day later in an effort to halt the spread of the deadly coronavirus.
Mayor Bill de Blasio said he decided to act because “our city is facing an unprecedented threat, and we must respond with a wartime mentality”.
Separately, the US is extending its European travel ban to include the UK and Republic of Ireland.
The US has confirmed 69 deaths linked to the pandemic and 3,774 infections.
New York City – which has the population of more than eight million – has recorded five deaths. Each of the victims – aged 53 to 82 – had underlying health conditions, officials say.
Last week, a top US health official admitted that the country’s testing system for coronavirus was failing.
President Donald Trump has said the US has “a tremendous testing set up where people coming in have to be tested”.
Correspondents say there is a growing sense of unease and confusion in America, with fears of a run on hospital beds and concern about childcare as tens of millions of children are sent home from school.
On Sunday, Mayor de Blasio said the city’s public schools would be closed from Monday until at least 20 April, in what he described as “the painful decision”.
He said officials would then review on whether to re-open, but did not rule out that schools would remain shut for the rest of the academic year.
Separately, Mayor de Blasio said that from 09:00 EDT Tuesday (13:00 GMT) the city’s restaurants, bars and cafes would be limited “to food take-out and delivery”.
“The virus can spread rapidly through the close interactions New Yorkers have in restaurants, bars and places where we sit close together. We have to break that cycle,” he said in a statement.
New York City has about 27,000 restaurants, according to the city’s health department.
Mayor de Blasio also said that “nightclubs, movie theatres, small theatre houses, and concert venues must all close”.
“This is not a decision I make lightly. These places are part of the heart and soul of our city. They are part of what it means to be a New Yorker,” his statement said.
