New York is at war with the coronavirus. Expect the same across the US, experts warn.

NEW YORK — New York City has rapidly become the epicenter of the U.S. coronavirus outbreak, paralyzing a city famous for never standing still as its leaders liken the crisis to war.

The city's bustling streets, thriving public transit and dense population made it uniquely vulnerable to the rapid spread of COVID-19. But other cities, suburbs and rural regions across the nation could see a similarly deadly situation unfold in the near future if swift action is not taken, multiple experts tell USA TODAY.

“New York is getting hit hard, and they’re getting hit first,” Ashish Jha said. The director of the Harvard Global Health Institute listed city after city and state after state that are showing early signs of a similarly devastating outbreak taking hold.

“New York is not an outlier,” Jha said. The virus is on track to hit "every city in America.”

White House coronavirus response coordinator Dr. Deborah Birx agreed.

"No state, no metro area will be spared," Birx said on NBC's "Meet the Press" on Sunday.

What is unfolding in New York City offers a case study in how the virus attacks all aspects of life, as well as what public health experts say needs to be done to beat it back.

The New York City outbreak keeps growing, with 678 deaths and more than 33,000 confirmed cases as of Sunday night, according to the Johns Hopkins University data dashboard.

In addition to the cluster of cases in New York City, Gov. Andrew Cuomo has noted the state's figures are higher than other states' in part because New York state is testing many more people.

According to data released by the New York State Department of Health, New York had administered 155,934 total tests as of Saturday afternoon, an increase of 10,181 – or nearly 7% – from the previous day. The next-closest state was Washington, with 59,206 tests administered as of Saturday afternoon, according to the Washington State Department of Health.

New York has the most confirmed cases in the U.S., exceeding 59,000, almost half the country's cases. The state has seen 965 deaths from COVID-19, an increase of almost 33% from the 728 reported deaths on Saturday.

Elsewhere in the nation, there are already signs that rural counties will soon see potentially devastating outbreaks.

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“The disease does not care if you’re in a big city, small city ... everybody is at risk,” said Jonathan Fielding, a distinguished professor in residence at University of California, Los Angeles' Fielding School of Public Health.

The warning comes even as U.S. leaders hope the virus' spread will be blunted by social distancing efforts.

"There is still a long battle ahead, but our efforts are already paying dividends," President Donald Trump wrote this week in a letter to governors. "As we enhance protections against the virus, Americans across the county are hoping the day will soon arrive when they can resume their normal, economic, social, and religious lives."

New York peak may be weeks away

In New York, the end of the crisis does not appear imminent. At a Friday press conference, Cuomo said he believed the peak was still about three weeks away.

The hardest-hit counties in the state outside of New York City as of Sunday morning were Westchester (8,519 cases), Nassau (6,445) and Suffolk (5,023), according to data released by the New York State Department of Health. Both Nassau and Suffolk, which are neighboring counties on Long Island, combined for 1,793 new cases.

New York City's dense population, role as an international travel hub and initial slowness to adapt social distancing measures set the city up for a deadly exponential expansion of the disease.

It all came together to make the city ripe for a virus that spreads through droplets coughed, sneezed or left behind on surfaces, a threat that makes identifying and isolating infected people crucial, health officials said.

With about 8.6 million residents, New York City is the most populous city in the U.S. It is more than twice as large as the next largest city, Los Angeles, at 4 million.

Early missteps that could be avoided elsewhere put that population at risk, Jha and Fielding said.

Mayor Bill de Blasio was “abysmal in his response to this disease," especially for the late implementation of social distancing measures, Jha said.

Fielding stressed that more testing and contact tracing could have made a big difference earlier in the outbreak.

By Friday, de Blasio issued a grim warning about what lies ahead for the city, saying that medical personnel already are working in what he described as “battlefield type conditions.”

“We’re going to need help from the outside to get through the sheer magnitude of the crisis ahead,” he said. “People need to be ready for battle.”

City is pulling out all the stops

Now that the city is in crisis, it's clear to Jha that it has been able to mobilize in a spectacular way to fight the virus. The effort to fight the New York City outbreak is a top national priority at this time.

“We will stop at nothing to protect the people of New York,” Trump said Saturday as he spoke from a pier at Naval Station Norfolk in Virginia, where he watched USNS Comfort, a naval hospital ship equipped with 1,000 hospital beds, set sail for Manhattan.

Cuomo said Friday that city hospitals had been asked to double their capacity, multiple temporary hospitals had been set up, testing efforts have been ramped up and medical supplies are being sourced from around the globe.

That's in addition to social distancing measures that emptied the city's streets, stemming the flow of tourists who flock by the millions to the Big Apple each year. The economic fallout of these measures is just starting to come into focus, although some expect the ripple effects could be felt for generations.

The state Department of Labor, for instance, received more than 80,500 unemployment insurance claims in one week in mid-March as New York workers were hit by the coronavirus-fueled economic shutdown.

Quick action needed across America

A national surge in cases like that seen in New York is not a foregone conclusion, Fielding said. But averting similar crises elsewhere requires swift action from officials and cooperation from residents.

"Every metro area should assume that they could have an outbreak equivalent to New York and do everything right now to prevent it," Birx said on NBC. "If they mitigate now before they start seeing cases in the emergency room and in the hospital – once you see those, the virus has been spreading for days to weeks. So this is really my call on every mayor to prepare now."

Rhode Island Gov. Gina Raimondo issued an order March 26 that mandated all travelers coming into the state from New York enter a 14-day quarantine upon their arrival.

After facing criticism from Cuomo that her order specifically targeted New Yorkers, Raimondo repealed it and issued a new one that broadened the need to quarantine to any travelers coming into Rhode Island from any other state.

On Friday in Florida, Gov. Ron DeSantis expanded an earlier order that added travelers from Louisiana entering the state to enter a 14-day quarantine. The order had previously only required that of travelers coming from New York. DeSantis also indicated he would suspend vacation rentals for two weeks.

And in New Orleans, which has become a hot spot as confirmed cases continue to soar, testing has ramped up. Louisiana Gov. John Bel Edwards said the New Orleans Ernest N. Morial Convention Center would be converted into a temporary emergency field hospital.

“Everybody should consider that the place that they work and the place that they live has a bit of New York City in it,” Fielding said.

Rural areas may be less likely to see the type of exponential spread New York City has suffered, but they also will be more strapped for resources and unable to command national attention to fight a devastating outbreak.

“I don’t think you can do enough too soon … time is not on your side. Time is the enemy," Fielding said.

The crisis in New York has already prompted action in less-populated areas of the country.

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The CEO of University of Iowa Hospitals and Clinics, Suresh Gunasekaran, said Friday: “We know we definitely won’t be hit as hard as New York. But even a lesser impact would still be significant.”

As he spoke from his office in Iowa City, the hospital was treating six COVID-19 patients and monitoring 25 others who were in their homes. Although the numbers were relatively small, Iowa’s number of positive tests for the coronavirus had doubled during the previous 48 hours, jumping to 235 from 124, he said.

Gunasekaran and his health care team were planning to convert an intensive care unit exclusively for COVID-19 patients. They had already started cross-training in critical care medicine for doctors and nurses in other medical disciplines, so they could help when the expected need arises.

“We know where this movie is moving next, so we’re doing our best to be prepared,” Gunasekaran said. “We’re just beginning to see a real surge in our state and our county.”

Contributing: Kevin McCoy, Rick Jervis, Deborah Berry, Matt Wynn, William Cummings, Christal Hayes, Ledyard King and Michael Collins, USA TODAY

This article originally appeared on USA TODAY NETWORK: Coronavirus in New York: City's crisis a preview of what's next for US