(Bloomberg) — The Trump administration on Friday declared a public health emergency and announced series of steps to halt the spread of the novel coronavirus, which has stricken China and spread to countries around the world.

President Donald Trump signed an order temporarily barring entry to foreign nationals who have visited China and pose a risk of spreading the illness, unless they are immediate relatives of U.S. citizens or permanent residents. The administration also said flights from China would be funneled through just seven U.S. airports.

“The risk of infection for Americans remains low,” Health and Human Services Secretary Alex Azar, who is coordinating the federal response, told reporters at a White House news conference. “With these and our previous actions, we are working to keep the risk low.”

U.S. citizens returning from China’s Hubei Province, the center of the outbreak, will face a mandatory quarantine. Americans traveling back to the U.S. from other areas of mainland China must undergo screening and monitored self-quarantine to ensure they are not at risk of spreading the virus.

The measures, which take effect at 5 p.m. Washington time on Sunday, apply to visits in the past two weeks. The quarantines last 14 days.

The White House’s announcement comes as the coronavirus continues to spread, triggering increasing alarm from health officials. The World Health Organization this week declared a global health emergency, giving the United Nations agency the power to coordinate response efforts.

Almost 9,700 cases have been confirmed in China with more than 200 deaths, said Robert Redfield, the director of the Centers for Disease Control and Prevention. He added that six cases have been confirmed in the U.S. and that 191 people are being monitored.

U.S. health officials have sought to reassure Americans the risk of contracting the virus remains low, but they have also said there is much they still do not know about the illness.

“This is a significant global situation that continues to evolve,” Redfield said.

Anthony Fauci, head of infectious diseases at the National Institutes of Health, said the U.S. decided to step up its efforts because of reports that a traveler from China spread the disease in Germany without showing any symptoms. He said that is different from the Ebola virus, which cannot be spread by people who are not very ill.

Health officials added that tests to detect the virus haven’t been used enough times to assure they are reliable. Only one in six U.S. cases of coronavirus has been detected through airport screening, they said.

All U.S.-bound flights from China will be routed to airports in New York, Chicago, San Francisco, Seattle, Atlanta, Honolulu and Los Angeles. More drastic flight restrictions are not currently being considered, according to Joel Szabat, a Transportation Department official.

Limiting the number of airports where flights to China can land will allow the U.S. government to streamline screening and set up quarantine centers, officials said.

The CDC announced earlier Friday it had issued a quarantine order of 14 days to 195 U.S. citizens evacuated from Wuhan, the capital of Hubei Province. It’s the first time in nearly a half century such an order was given.

On Thursday, the State Department issued its highest level do-not-travel advisory for China, warning American citizens there they could be subject to travel restrictions with little to advance notice and urging them to “consider departing using commercial means.”

The rapid outbreak of the virus has sent financial markets tumbling. The S&P 500 Index on Friday erased all of its 2020 gains and the Dow Jones Industrial Average as investors grow worried about how the illness could effect the world economy.

Federal Reserve Chairman Jerome Powell said on Wednesday that the central bank is “very carefully monitoring the situation” and “there will clearly be implications at least in the near term for Chinese output.”

–With assistance from Justin Sink.

To contact the reporter on this story: Jordan Fabian in Washington at jfabian6@bloomberg.net

To contact the editors responsible for this story: Alex Wayne at awayne3@bloomberg.net, Justin Blum, John Harney

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