Any foreign national who has traveled within China in the last 14 days will not be allowed to enter the United States, according to a proclamation from President Trump. The action is to prevent the spread of the new coronavirus, said US Secretary of Health and Human Services Alex Azar. Azar also said that he was declaring a public health emergency in the US.

The new coronavirus has sickened nearly 10,000 people worldwide in nearly two dozen countries, and it has killed 213 people in China.

Any US citizen who has traveled in China will undergo health screening upon entry into the country and will be asked to self-quarantine for 14 days. US citizens who have traveled to Hubei province, where the virus originated, will be held under mandatory quarantine for 14 days after they return to the US. Based on the latest available data, 14 days is the longest estimate of the time it takes for people to develop symptoms after they’re infected with the virus. It is still not clear how easily the virus can spread from one person to the next, although preliminary data suggests that people who do not have symptoms can still infect others.

All incoming flights from China will be restricted to seven airports to consolidate passenger screening and evaluation: John F. Kennedy International Airport, Chicago O’Hare International Airport, San Francisco International Airport, Seattle-Tacoma International Airport, Hartsfield-Jackson Atlanta International Airport, Los Angeles International Airport, and Daniel K. Inouye International Airport in Honolulu.

The new policies contradict advice from the World Health Organization

The policies will take effect Sunday, February 2nd at 5PM ET.

Immediate family members of US citizens and permanent residents will be allowed to enter the country, Azar said. They’ll also be monitored under quarantine. Yesterday, the US State Department said that US citizens should not travel to China at all — giving its strongest possible travel advisory, a level 4, which is reserved for places with a “greater likelihood of life-threatening risks.” After that decision, US airlines American, Delta, and United Airlines suspended flights to and from China.

The new policies contradict advice from the World Health Organization (WHO), which said yesterday that countries should not restrict travel or trade in their response to the new virus. The WHO said that the outbreak of the coronavirus is a public health emergency of international concern.

The Centers for Disease Control and Prevention (CDC) is already holding 195 US citizens who had been evacuated from Wuhan, China in mandatory quarantine. It is the first time the CDC has held anyone in quarantine since the 1960s.

Coronavirus still poses a low risk to the general public in the US, said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. There are six confirmed cases of the coronavirus in the US: five in people who had recently traveled to China, one in the husband of one of those patients.

Update January 31st, 4:20PM ET: Updated with new information on travel restrictions.

Update January 31st, 5:01PM ET: Updated with additional context.