Spain has said it hopes to open up to overseas travellers from June, as plans for an EU-wide digital certificate go before the European Parliament.
Tourism minister Fernando Valdés said a pilot test would take place in May so that Spain would be ready to receive travellers the following month.
The EU has been working on a digital pass in time for the summer holidays.
It would cover anyone who is either vaccinated against Covid-19, has a negative test or recently recovered.
Several countries have already begun using digital or paper passes to help ease local lockdowns.
Mr Valdés told a travel conference in Mexico his country would be "ready in June to tell all travellers worldwide that you can visit us".
However, any scheme to open up to non-European tourism would be dependent on the EU's digital green certificate and Mr Valdés said it was not a magic wand.
Spain has long been a favourite destination for British holidaymakers but they will have to wait several more weeks to find out if they can start booking. From 17 May, overseas leisure travel could resume for people in England under Prime Minister Boris Johnson's roadmap for easing restrictions.
The UK government is also expected to set out which countries fall into the "green", "amber" and "red" categories under a new risk-based traffic light system. These will determine testing and quarantine requirements for travellers when they return from various countries.
In a debate ahead of Wednesday's EU Parliament vote on the new scheme, EU Justice Commissioner Didier Reynders warned of the possibility of "fragmentation across Europe" if an agreement could not be reached.
"We would risk having a variety of documents that cannot be read and verified in other member states. And we risk the spread of forged documents, and with it, the spread of both the virus and the mistrust of citizens," he said.
Dutch MEP Jeroen Lenaers stressed that the proposed system would ensure "full equality and avoids discrimination between those who have been vaccinated and those who have not" by allowing travel to people who had tested negative or had recovered from the virus.
However, questions remain about how long immunity lasts after an infection and whether further jabs are needed amid the rapid spread of more contagious Covid variants.
Other issues include what data would be used to prove an individual was not infected with coronavirus and privacy concerns.
How will the passes work?
Key to the EU's digital certificate is a QR code - a machine-readable graphic code made up of black and white squares - that contains personal data and the EU's Commission says it will be safe and secure. It is working with the World Health Organization to ensure the certificate is recognised beyond Europe.
The 27 member states also want to include non-EU countries such as Norway, Iceland and Switzerland, with officials saying earlier this week that vaccinated travellers from the US may also be able to visit Europe this summer.
However, the European Commission has said that there have been "no contacts" with the UK over the issue.
The UK government is working on a digital system for international travel that would prove travellers' vaccination status. Transport Secretary Grant Shapps told the BBC he would discuss the issue next week with G7 industrialised countries, including the US and Canada.
More details were expected to be released in the next few weeks, he added.
A number of countries have already begun unveiling their own passport systems.
In Denmark, the Coronapas app is being used to allow customers who have been vaccinated or recovered from an infection to enter bars, restaurants and museums.
A similar scheme in Israel, which has one of the highest levels of vaccinations in the world, permits users to access hotels, gyms and theatres. The "Green pass" has also created travel opportunities for Israeli citizens, following deals with Greece and Cyprus.