Federal officials declared a public health emergency and will be restricting entry into the United States in light of the 2019 novel coronavirus that has killed at least 200 people and infected nearly 10,000 more worldwide.

Health and Human Services Secretary Alex Azar told reporters Friday that President Trump would sign a proclamation temporarily suspending entry to foreign nationals deemed to pose a transmission risk.

Azar also said any U.S. citizen who traveled to China's Hubei province within the past 14 days before arriving home would be subjected two weeks of mandatory quarantine. And citizens who traveled to any other regions in China would undergo a “proactive entry health screen” and 14 days of monitored self-quarantine.

“The risk for infections for Americans remains low,” Azar said, adding that these steps were “measured” reactions that would help officials deal with “unknowns” surrounding the virus.

Earlier Friday, the Centers for Disease Control and Prevention (CDC) said they were putting 195 people who recently returned from China under quarantine for two weeks, dubbing it an “unprecedented” step that was now warranted.

“We are preparing as this is the next pandemic, but hopeful this is not and will not be the case,” Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, said on a call with reporters. “We would rather be remembered for overreacting to under-reacting.”

The move came after one of those recently-returned travelers reportedly attempted to leave the March Air Reserve Base in Riverside, California, after arriving from Wuhan, China. The CDC declined to provide more information on the individual.

There are currently over 9,800 cases of coronavirus in China, while the number of confirmed cases in the United States rose to seven on Friday. California officials announced a man who recently traveled to Wuhan had tested positive for the virus. Only one of the seven cases, the husband of a woman who recently traveled abroad, had been spread in-country, the CDC said previously. No one had died as a result of infection in the United States by the CDC's latest count.

But Messonnier pointed to the most recent number of cases in China, which she said represented a 26 percent increase over Thursday's numbers, as a cause for growing vigilance. She also mentioned an increasing number of reports of person-to-person spread, including growing evidence that the 2019 novel coronavirus can be spread by people who have not yet experienced symptoms. The New England Journal of Medicine on Thursday released a study describing a case in Germany that appeared to show the spread of the virus from a person who traveled to China to several others.

“The current scenario is a cause for concern,” Messonnier said.

When asked if the coronavirus were more dangerous than the flu, Messonnier said there appeared to be “significant mortality related with this disease” based on cases coming out of China. However, she still didn't recommend face masks for the general public and urged people to stay calm.

“Please do not let fear guide your actions,” she said, adding that the public shouldn't assume Asian Americans have the virus amid reports of surging xenophobia against people of Chinese descent worldwide. “There are about 4 million Chinese-Americans in this country.”