BEIJING — China has launched a system of so-called "virus passports" for its citizens planning cross-border travels, joining other countries issuing similar documents. A few countries, including Bahrain, have already introduced certificates identifying vaccinated people. Similar schemes are under discussion in the United States and the European Union. Chinese citizens can download the new certificates and use them to enter and leave the country, with the foreign ministry saying the system was intended "to help promote world economic recovery and facilitate cross-border travel". However, the Chinese scheme is not mandatory and, as it is only available for Chinese citizens, it is not yet clear how it could work internationally . Foreign Minister Wang Yi said on Sunday the aim of the certificate is to achieve mutual verification of information such as nucleic acid testing and vaccination and contribute to safe and orderly interaction of people. — Agencies