The Biden administration will require airline passengers traveling from China to test negative for Covid before entering the U.S. as concern grows that widespread transmission of the virus in the world’s most populous country could result in new variants.

All airline passengers 2 years and older originating from China, Hong Kong or Macau will be required to get tested for Covid-19 no more than two days before their flight to the U.S. and show a negative result to the airline upon departure, the Centers for Disease Control and Prevention announced on Wednesday.

The requirements, which apply regardless of nationality and vaccination status, start Jan. 5. Travelers can get a PCR test or a rapid self test that is administered and monitored by a telehealth service. The rapid test must be authorized by the Food and Drug Administration or the relevant national authority.

Airline passengers flying through Incheon International Airport in South Korea as well as Toronto Pearson and Vancouver International Airports in Canada will also need to test negative for Covid before heading to the U.S. if they were in China 10 days beforehand.