Transport Secretary Grant Shapps has said he “cannot rule out” that other countries could be included under the UK’s quarantine measures.
Mr Shapps made the comment to reporters as he returned to the UK having cut short a family holiday to Spain.
It follows the UK Government’s decision to require travellers from the country to isolate for 14 days on their return to the UK following a rise in Covid-19 cases.
Mr Shapps will now need to isolate as a result of the restrictions being imposed.
He said: “We absolutely have to act the moment we get the information and that’s exactly what happened with Spain as we saw and as we’ve seen over the weekend where there was over 6,100 cases – the highest since the peak in March over there.
“It was the right thing to do and it’s why the whole of the UK did (it) at the same time.
“I can’t therefore rule out other countries having to go into the quarantine as well.”
Mr Shapps said he could understand the frustrations of those impacted by the measures, although he insisted that it was “essential” that the Government acted when it did.
Some travel companies, including Tui and Jet2, have already announced that flights to destinations in Spain will be suspended into August.
Mr Shapps said: “I very much understand (the frustrations), it obviously had an impact on me and my family and I’m very, very sorry and upset for the thousands of Brits who are either away or perhaps even haven’t managed to go away this summer as well to Spain.
“But it’s absolutely essential we acted when we did, it’s why all four nations of the United Kingdom acted together and the figures since have turned out to justify that action.
“We have to, I think, have a clear message and make sure that we act by adding entire countries to that list for the time being.”
The Transport Secretary also explained that the exclusion of certain Spanish islands from the measures taken by the UK Government had been considered.
Spain’s Prime Minister Pedro Sanchez described the restrictions brought in by the UK as an “error”, with Madrid having urged the UK to exclude the Canaries and Balearics from its quarantine requirements.
Mr Shapps said: “We did have a look at whether certain islands could be included (on the list) and not others.
“Chris Whitty, the chief medical officer, was very clear with us that he was concerned about the data, we’d seen how the data had come very fast forward in Spain in 20, 48 hours, it had gone up by 75%.
“It had doubled in just a few days. He was concerned to see what was happening in the islands and that’s why we make it a whole-country approach in these things.”
Leaders from the UK’s aviation, travel and tourism industries have written to Prime Minister Boris Johnson calling for targeted regional travel corridors and the development of Covid-19 testing.
In a letter seen by the PA news agency, bosses at firms including British Airways, Airlines UK, Jet2 and Heathrow Airport told Mr Johnson the introduction of quarantine measures for Spain represents “the latest significant blow to a sector which now risks being permanently scarred”.
They said regional travel corridors would be a “clear way forward” and represent a “more nuanced approach to quarantine”.
Bosses also said that Covid-19 testing has the potential to be a “game-changing additional tool” for authorities to safely open up travel without quarantine from countries or regions deemed higher risk, such as the US.
They added: “We will collectively continue to work hard on behalf of our customers facing uncertainty and disruption.
“At the same time, we are calling for the implementation of a structured announcement timeline and, working with the sector, for the publication by Government of a strategy for the testing of passengers in the UK, alongside a regionalised approach to travel corridors, as a matter of urgency.”