Denmark, Slovakia and Iceland have been added to England’s travel quarantine list – meaning travellers returning from 4am on Saturday will have to self-isolate for two weeks.
The Caribbean island of Curacao has also been added to the list.
The government’s “red list” is aimed at stopping coronavirus spreading from countries with high infection rates.
Anyone who fails to quarantine after returning from these countries – apart from a small list of exemptions – faces a fine starting at £1,000.
No countries have been removed from the red list this week, Transport Secretary Grant Shapps confirmed.
Scotland, Wales and Northern Ireland usually update their own lists following the UK government’s announcement of its changes for England.
The government makes its quarantine decisions based on – among other things – whether a country’s weekly infection rate is above 20 cases per 100,000 people.
The latest figures show Denmark has a weekly infection rate of 45.3 per 100,000, surpassing the UK’s 38.6 per 100,000.
Slovakia is at 24.6 per 100,000, while Iceland is at 50.7.
Paul Charles, chief executive of travel consultancy The PC Agency, said: “It’s sad to see the list of countries growing on the quarantine list in line with the resurgence of COVID-19 in several parts of the world.
“It now makes even more sense for traveller testing to be introduced as soon as possible, reducing quarantine times and enabling economies to get going again.
“A co-ordinated, global programme, combining testing with short quarantine periods if necessary, would help protect lives and livelihoods.”