Japan will issue digital vaccine certificates to citizens having received at least one COVID-19 vaccination. The certificates will be available to foreigners in Japan either resident there or returning to their home countries.

Japan's certificate will follow international standards and be accessible on a mobile application so holders can present proof of vaccination when traveling overseas. It will also be linked to a system monitoring the progress of Japan's vaccination program.

China and the European Union earlier announced their own vaccine passports. The EU will be ready by June. This document intends to get travel moving across borders "without discrimination."

It will have a quick response code and a digital signature to protect against falsification. The certificate can be digital or on paper. It will allow those vaccinated against COVID, or who have tested negative or recently recovered from the virus, to travel across all member states.

The China passport also uses an app with QR code for authentication. The passport will likely first be put to use for travel between the mainland and Hong Kong and Macao.

The World Health Organization, however, has called on governments not to introduce vaccination or immunity requirements as a condition of entry for international travel.

"Being vaccinated should not exempt international travelers from complying with other travel risk reduction measures," the organization said.