Transport Secretary Grant Shapps said the NHS app is being worked on to become a coronavirus health certificate for international travel by the government.
He told Sky News: “In terms of vaccine certification, I can confirm we are working on an NHS application, actually it will be the NHS app that is used for people when they book appointments with the NHS and so on, to be able to show you’ve had a vaccine or you’ve had testing.
“I’m working internationally with partners across the world to make sure that system can be internationally recognised, as that’s the way forward.
“Actually, I’m chairing a meeting of the G7 secretaries of state for transport, my equivalents from America and Canada and all the G7 countries, next week on exactly this subject.”
Earlier, the Spain's tourism minister said it would be welcoming tourists back from June.
The EU previously set out plans for coronavirus vaccine certificates that could be used by UK holidaymakers this summer.
Digital Green Certificates will be accepted as “proof” a person had a Covid-19 jab, received a negative test result or recovered from the virus, according to the European Commission’s proposal.
Spain – which welcomed 18 million Brits in 2019 – says a digital certificate scheme is currently being trialled with a view to a wider roll out in June.
Under the UK's roadmap, the earliest date international travel can resume from the UK is May 17.
A traffic light system is expected to be unveiled which would see a system of green, amber or red lights used for countries, depending on their rate of infection and new variants.
