South Korean Prime Minister Han Duck-soo inspects a Covid-19 testing station on Monday for people arriving from China at Incheon International Airport in Seoul. The country had announced compulsory Covid-19 testing for such arrivals on Friday. The rule will remain in effect through February. Photo: Kim Jae-Hwan/VCG

Officials guide travelers from China through the arrival testing procedure at Incheon airport. South Korea also imposed visa restrictions on Chinese citizens and limited flights from China after its neighbor announced it was relaxing rules restricting international travel. Photo: VCG

Passengers from Shanghai in protective suits wait to get tested for Covid-19 after arriving at Narita International Airport in Japan on Friday. Photo: Yomiuri Shimbun/VCG

Visitors from Shanghai line up to get tested at Narita International Airport. Anyone who tests positive will be quarantined for seven days. Photo: VCG

A passenger arrives Tuesday at Aeropuerto Adolfo Suárez Madrid-Barajas airport in Madrid, Spain. Arrivals from China need to show that they have been tested for, vaccinated against or recovered from Covid. They also have to get their temperature checked to see if they have a fever. Photo: VCG

A passenger from China leaves a Covid-19 testing area Sunday at Paris Charles de Gaulle Airport in Paris, France. Photo: Aurelien Morissard/VCG

Medical staff wait for travelers from China at a testing center in the Paris airport. French rules require travelers from China to wear masks and to provide negative Covid-19 test results from the last 48 hours. Photo: Julien De Rosa/VCG

Workers wearing protective gear help Chinese visitors leave Leonardo da Vinci International Airport in Italy on Thursday. Italy imposed mandatory Covid-19 tests for arrivals from China on Dec. 28. The rules will remain in effect through Jan. 31. Photo: VCG