Greek Prime Minister Kyriakos Mitsotakis has called for an EU-wide COVID-19 vaccination certificate to help restore cross-border travel, Reuters reports.

Greece, which aims to revive tourism ahead of the start of the summer season, has already created its own standardized certificate confirming that a person has been vaccinated.

In a letter to the President of the European Commission, Ursula von der Leyen, Mitsotakis proposed extending this scheme to all 27 EU countries. The certificate can be used for boarding all types of transport. 

"While we are not going to make vaccination compulsory or a prerequisite for travel, persons who have been vaccinated should be free to travel," he said in the letter.

"(It is) urgent to adopt a common understanding on how a vaccination certificate should be structured so as to be accepted in all member states," Mitsotakis added.

The difficulty in agreeing a common EU digital Passenger Locator Form (PLF), created last year to track passenger movements, has shown that there is an urgent need for high-level EU efforts to move forward, he said. The letter says that if the EU countries can agree on a common formula, "we can then push the issue forward in the relevant international fora, thus contributing to the re-establishment of mobility on a global scale," the letter said. 

"For countries such as Greece, which are dependent on tourism, it's imperative that this issue is resolved before the summer season."