The White House announced Friday a ban of all foreign nationals traveling to the United States who have traveled in China in the last two weeks.

The ban applies to all foreign nationals who have traveled in China within the last 14 days and will be denied entry into the United States and will become effective at 5:00 p.m. EST on Sunday, February 2.

The ban was announced by Health and Human Service Secretary Alex Azar at the White House press briefing room. There will be an exception for immediate family members of American citizens and permanent residents.

Any United States citizen who has traveled specifically in the Hubei province of China in the last 14 days faces a mandatory quarantine of up to two weeks. United States citizens who have been to China in the last 14 days will undergo health screening and then will be asked to self-quarantine for 14 days.

“These prudent, targeted, and temporary actions will decrease the pressure on public health officials screening incoming travelers, expedite the processing of U.S. citizens and permanent residents returning from China,” Azar said.

Azar said that the ban was a “prudential” step to deal with the unknown details of the virus although he fully expected more cases in the United States.

He also reassured Americans that there was still a low risk of the disease spreading significantly into the United States, but that precautions were necessary.

“The risk of infection for Americans remains low and with these and our previous actions we are working to keep the risks low,” he stated.

Azar declared a public health emergency in the United States and said that health officials will focus all efforts on screening and protecting American citizens. Many American airlines have already stopped flights to China.

“We’ve seen a significant reduction, in people from the U.S. going to China, people from China coming to the U.S. already,” he said.

American citizens and foreign nationals returning from China will be redirected to seven airports for screening — JFK, SEA, ATL, ORD, HNL, LAX, SFO.