Japan tightened Monday its rules on coronavirus test certificates needed to be submitted by all passengers upon arrival at Japanese airports, with those failing to meet required conditions to be denied entry into the country in principle.

Since March, Japan had been asking airlines to deny boarding of passengers without negative coronavirus testing results taken within 72 hours of departure.

A passenger from overseas (L) has his coronavirus test certificate checked at Narita airport in Chiba Prefecture on April 19, 2021. (Kyodo)

Until Sunday, the country's quarantine authorities, however, still allowed those who had come to Japan with insufficient certificates to stay at a designated facility and retake a coronavirus test after three days.

But the authorities said such alternative treatment will no longer be available, as the country reels from surging infections

To enter Japan, a passenger needs to obtain a certificate that proves negative results for the virus based on nasopharyngeal or saliva samples, which need to be taken within 72 hours before departure.

Japan does not approve antigen or antibody tests as certificates for entering the country.

Given the spread of the virus, Japan currently only allows entry of Japanese nationals and resident foreigners as well as foreigners "with special exceptional circumstances."

Japan is also requesting domestic and foreign airlines to restrict the number of passengers planning to enter the country.