All restaurants must be limited to take-out and all bars will close under a tri-state order affecting New York, New Jersey and Connecticut in an attempt to slow the spread of the coronavirus outbreak.

Effective at 8pm on Monday, all gyms, movie theatres and casinos in the region will also be closed, according to New York Governor Andrew Cuomo. Performance venues were also forced to close over the weekend.

Grocery stores and pharmacies will remain open.

New York's liquor authority will also issue guidance on Monday to allow bars, wineries and distilleries to sell alcoholic beverages to-go.

Governor Cuomo says the states are aiming to prevent a wave of potential patients from "crashing" the healthcare system. "Social distancing is the best way to do that", he said.

The Covid-19 outbreak "doesn't care about state borders", the governor said. "These temporary closures will last as long as is necessary to protect the public health."

He argues that the coordination with neighbouring states comes at the absence of "uniform set of rules" from the federal government, following his criticism of Donald Trump's handling of the crisis. Instead, "regional coordination is imperative", Mr Cuomo said.

"The faster and better societies close down, the sooner they reopen", he said.

On Sunday, New York City Mayor Bill De Blasio announced the closures of the city's public school system, the largest in the US, serving 1.1m students.

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He estimated the closures would last through 20 April but suggested they could remain in effect through the school year, if not longer, as the mayor made the difficult decision to turn thousands of children — many from poor households — away from what for many people is a reliable social safety net.

As the nationwide total of confirmed cases climbs closer to 4,000, New York City has more than 400, up from 329 on Sunday, while the number of confirmed cases in the state grows closer to 1,000, the most in the nation. Seventeen per cent of those cases involved hospitalisations.

Seven people in the state have died.

As of Sunday, New Jersey had 98 confirmed coronavirus infections, up dramatically from 31 the day before. Two people in the state have died.

Health officials warn that those numbers obscure the total number of infected people in the US.

New York City's Health Department has urged residents to behave as it they already have been exposed to the virus.

Though the state has taken on some of the most dramatic public health responses in the wake of the crisis, Governor Cuomo said he doesn't believe it's enough to "flatten the curve" to prevent overwhelming a fragile hospital system.

He has urged the federal government to activate the Army Corps of Engineers to build hospitals and triage centres to meet the potential, if not likely, need for a surge in new patients.

Without that federal support, the governor said the state is likely to work with the National Guard and private developers to find existing buildings that could be retrofitted as hospitals including dorms and former nursing homes.

He said: "We'll do everything we can but we need more federal assistance."

The governor also warned that he could ask hospitals to cancel non-essential elective surgeries: "We will need that capacity."

Mayor De Blasio told reporters on Monday that the city is looking to add more than 8,000 hospital beds as officials look to build the capacity to meet a growing patient list.

A facility on Roosevelt Island can hold 350 beds and be ready within the next month, he said. Two hospitals in the Bronx will support another 270 beds.

In Brooklyn, a recently built nursing home that is yet to open will hold another 600 beds.