The United States will require travelers from China, Hong Kong and Macau to show a negative COVID-19 test before entering the U.S. as restrictions lessen and cases surge in China.

The U.S. Centers for Disease Control and Prevention announced the measure Wednesday to go into effect on Jan. 5 for all passengers over the age of 2. Passengers must show a negative PCR or monitored antigen test no more than two days before their departure, whether it is a direct flight or an indirect one through another country.

The monitored test must be overseen by a telehealth service or a licensed provider and authorized by the U.S. Food and Drug Administration.

The CDC pointed to the surge in COVID-19 cases in China and "the lack of adequate and transparent epidemiological and viral genomic sequence data being reported from" that country.

"Reduced testing and case reporting in (China) and minimal sharing of viral genomic sequence data could delay the identification of new variants of concern if they arise," the CDC said in a news release.