The European Union's 27 leaders are debating their shared Covid-19 strategy on Thursday, with several member states vying to break rank and offer privileges to vaccinated foreign visitors.
The bloc is split between member states like France and Germany, which are reluctant to start linking shots to travel rights, while another camp, led by tourism-minded Greece and Cyprus, is keen to move forward more quickly.
Nicosia has already signed a deal with Israel allowing citizens who've had the jab in for holidays from April 1.
Austrian Chancellor Sebastian Kurz said that if the bloc can't agree on benefits for people who are vaccinated, tested or immune from a coronavirus infection, his nation and like-minded countries will soon go ahead with such measures.
"I think that this project has to be implemented in spring - if not in all of Europe, we will have to do it on a national level, and with agreements with other countries that have similar policies," he told a press conference ahead of Thursday's talks.
He stressed that his planned "digital green passport" on people's mobile phones could offer access to restaurants, cultural events, sports and tourism, not only for those who have received Covid-19 shots, but for everyone with a recent negative test.
Countries with major tourism industries, like Austria, Greece, Italy and Spain, are mulling similar ideas, he said.
Bulgarian Prime Minister Boyko Borisov made similar comments right before the leaders' videoconference kicked off.
However, the science on whether vaccinated people can still infect others is not yet decisive. Moreover, with shots in short supply, there are also concerns about fairness.
Just over 6% of the EU population has had at least one dose so far, according to figures compiled by the University of Oxford's Our World in Data project.
"Vaccine passports" could also exclude those unwilling or unable to get a shot.
No decision was expected on Thursday.
How to recognize certificates
At present, discussions are focused on how to mutually recognize vaccination or testing certificates, according to EU and diplomatic sources. Many are keen to see a global framework in place, to ensure any EU certification scheme could also function elsewhere.
The 27 countries unanimously pledged to restrict non-essential travel within and into the bloc a few weeks ago. A draft joint statement shows they plan to stick to this position.
Another contentious issue is border closures.
The European Commission chided Germany, Belgium, Hungary, Denmark, Sweden and Finland earlier this week for sealing off frontiers to neighbours within the EU free movement area in a bid to curb the spread of new coronavirus variants.
The EU executive arm is pushing member states to stick to a framework for travel within the bloc agreed just a few weeks ago, based on shared risk assessments.
Finally, EU leaders are to discuss ways to step up their inoculation drives, with the 27 member countries lagging behind frontrunners like Israel and Britain in the race to vaccinate their populations.
"We need to urgently accelerate the authorization, production and distribution of vaccines, as well as vaccination," the heads of state and government are set to pledge, according to the draft statement.
The member states are also to throw their weight behind the European Commission's recent efforts to work with industry and address bottlenecks, the draft shows, after weeks of tension with pharmaceutical firms over delivery days.
