Last month, Wuhan was overwhelmed with thousands of new cases of coronavirus each day. But in a dramatic development that underscores just how much the outbreak has pivoted toward Europe and the United States, Chinese authorities said on Thursday that the city and its surrounding province had no new cases to report.

The news offered a rare glimmer of hope for the rest of the world as it battles the virus, and perhaps a lesson in the strict measures needed to halt its spread. It came as President Donald Trump likened the fight to “a war” and invoked emergency powers that allow him to compel manufacturers to deal with the pandemic.

Wuhan was where the outbreak first took hold and thousands once lay sick or dying in hurriedly constructed hospitals. But Chinese authorities said on Thursday that all 34 new cases recorded over the previous day had been imported from abroad.

“Today we have seen the dawn after so many days of hard effort,” said Jiao Yahui, a senior inspector at the National Health Commission.

Still, the virus continued to take its toll elsewhere, both human and economic. Stocks tumbled again on Wall Street on fears of a prolonged recession, falling so fast they triggered another automatic trading halt, while major US auto manufacturers said they were shutting down their North American factories.

The Dow Jones Industrial Average shed more than 1,300 points on Wednesday, or over 6 per cent, and has now lost nearly all of the gains it had posted since Trump’s inauguration. Oil dropped below $21 per barrel for the first time since 2002. Shares in Asia continued their slide on Thursday.

Around the world, countries closed down their borders, leaving some to wonder how they would get back home. In the Pacific, Australia and New Zealand shut out tourists, allowing only citizens and residents to return, while Fiji reported its first case, a worrying development in a region with poor healthcare.

The US and Canada both closed their borders to all but essential travel and Trump said he plans to assert extraordinary powers to immediately turn back to Mexico anyone who crosses over the southern border illegally.

Mexico, meanwhile, reported its first death from the virus and closed its popular spring equinox visits to the Pyramids of the Sun and the Moon at Teotihuacan.

The White House pressed Congress to swiftly pass a potentially $1 trillion rescue package to prop up the economy and speed relief checks to Americans in a matter of weeks.

Calling himself a “wartime president,” Trump invoked the Defence Production Act of 1950 to steer industrial output and overcome shortages of face masks, ventilators and other supplies as hospitals brace for an expected onslaught of cases.

The Korean War-era law gives the president extraordinary authority to compel industries to expand production and turn out vital materials. It was most recently used after the 2017 Puerto Rico hurricane to speed up contracts for food and other necessities.

Trump likened the coronavirus fight to measures taken during World War II and warned of national sacrifices ahead.

While China did not report any new cases in Wuhan or Hubei province it did record eight additional deaths.

Jiao said the “double-zero” increase, which followed several days of improving numbers, meant their control and medical treatment methods were working well.

Wuhan has been under a strict lockdown since January. Officials are moving to loosen travel restrictions, but only inside the surrounding province of Hubei where most checkpoints will be taken down. Wuhan remains cut-off, with only those with special permission allowed to travel in or out.

The lockdown will be lifted there only if no additional cases are reported for two consecutive weeks, which may happen next month, Li Lanjuan, a member of the Chinese Academy of Engineering, was quoted as saying.

The virus has infected more than 218,000 people worldwide and killed over 8,800, mostly in China, Italy and Iran. The United Nations warned that the crisis could lead to the loss of nearly 25 million jobs around the world.

More than 84,000 people overall have recovered from the virus, which causes only mild or moderate symptoms such as fever and cough in most cases. Severe illness is more likely in the elderly and those with existing health problems.

Though China still has the largest number of cases, most of its patients have recovered. China even sent medical supplies to hard-hit France, returning a flavor done by the French weeks ago.

But in a grim illustration of the pandemic’s shift, deaths in Italy were nearing China’s toll. Italy had more than 2,900 dead after a record one-day total of 475; China’s overall toll was around 3,200. Iran has also been hit hard, with more than 1,100 deaths.

Around the globe, governments took increasingly drastic measures to fight the epidemic and the threat of a recession, in some cases using emergency powers.

California’s governor warned that martial law could be imposed. The mayor of New York said the city’s 8.6 million residents should be prepared for a lockdown. The US Census Bureau suspended field operations for two weeks, soon after it began its once-a-decade count of American people.

Czech authorities used emergency powers to raid a warehouse and seize hundreds of thousands of face masks. And Hong Kong widened the use of electronic wristbands that monitor people under self-quarantine.

With a growing number of Americans thrown out of work by the near-shutdown of much of the US economy, Trump also said the Housing and Urban Development Department will suspend foreclosures and evictions from public housing.

The Trump administration’s plan for issuing relief checks to Americans calls for the payment of $500 billion in two instalments over the next two months. The amounts have yet to be decided but would be based on income and family size.

Ford, General Motors and Fiat Chrysler, along with Honda and Toyota, said they will shut all of their factories in the US, Canada and Mexico. The closing of Detroit’s Big Three alone will idle about 150,000 workers, who are likely to receive supplemental pay in addition to unemployment benefits.

At GM’s pickup truck assembly plant in Flint, Michigan, workers have been fearful since the virus surfaced in the US, said Tommy Wolikow, who has two young daughters.

“That’s the thing that I was scared the most about, being the one to bring it home to them,” he said.

The US has reported more than 9,400 coronavirus cases and at least 138 deaths, about half of them in Washington state, where dozens of residents from a suburban Seattle nursing home have died.

Rep. Mario Diaz-Balart of Florida is the first known member of Congress to test positive for the virus. Other members of Congress have self-quarantined, but none have reported positive test results.

Miami Mayor Francis Suarez, who last week announced he tested positive, is sharing his experience in a daily YouTube diary and on Twitter as he runs the city from home isolation. His wife and children are staying with relatives.

“The longer I live with COVID-19, the more I understand just how crucial social distancing is,” Suarez wrote.

Scientists have no doubt the true number of people infected is higher than reported because of the possibility that many mild cases have gone unrecognised or unrecorded, and because of the lag in large-scale testing in the US

In the first breakdown of its kind in the US, the Centres for Disease Control and Prevention said that the nation’s coronavirus deaths so far mirror what has been reported in other countries, with about 4 out of 5 fatalities occurring in people 65 and older, and no deaths in children.