The UK is in no hurry to add countries to its green list for international travel, Health Secretary Matt Hancock said.
A dozen countries and territories are on England’s green list, allowing for relatively free travel, but most are categorised as amber or red, meaning travellers need to quarantine at home or in an approved hotel on arrival.
The limited list comes amid concern over imported cases of coronavirus and the potential for a new variant to escape vaccine-induced immunity.
Mr Hancock said on Tuesday the UK government would take a “cautious approach at the borders in order to protect the progress we are making”.
"People would be loath to see all this progress we have made at home, thanks to the vaccination effort and thanks to the sacrifices people have made during lockdown, to be put at risk by going too fast at the borders," he told BBC's Radio 4 Today programme.
“But on the other hand we are seeing countries get this virus under control in the same way we appear to get it under control - countries like Portugal and Israel, like Australia and New Zealand.”
The World Health Organisation on Monday praised the UK’s traffic light system as an important step towards reopening the “mothballed” travel industry.
Dr David Nabarro, WHO’s special Covid-19 envoy, said “finding a way to restart despite this fear is what we all have to do”.
“We must maintain a very vigilant posture in the coming months,” he said.
The potential risks of resuming widespread international travel were demonstrated again on Monday after the WHO declared the coronavirus variant first found in India as a “variant of global concern”.
The body said early studies suggested antibodies were less effective on the variant in small-sample lab studies.
However, it cautioned that it was far too early to interpret this to mean that the variant might have more resistance to vaccine protections.
The UK is surge testing in a number of areas in response to the India variant, with more than 520 infections discovered up until May 5.
Prof Graham Medley from the London School of Hygiene and Tropical Medicine said how fast the UK returns to normal depends on the prevalence of mutations.
“If the vaccines continue to work and we don’t have any nasty variants then we could be completely back to normal by the end of the year,” he said.
“But then on the other hand there are variants. If the impact of vaccines wane and we aren’t able to get boosters then we could be in a very different position.”
England, Scotland and Northern Ireland recorded zero coronavirus deaths on Monday, while Wales recorded four deaths. There were 2,357 new cases across the UK.
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