Cyprus and Lithuania have been added to the UK's coronavirus quarantine list.
Transport Secretary Grant Shapps announced that travellers returning from these countries will be required to self-isolate for 14 days.
The measures will come into force from 4am on Sunday, applying to people arriving in England, Wales and Northern Ireland.
This comes after the seven-day rate of coronavirus cases increased in both countries.
Cyprus currently has a rate of 112 cases per 100,000 people while Lithuania has 140 cases per 100,000 people, according to data collected by the European Centre for Disease Prevention and Control.
The UK currently has a seven-day rate of 230 cases per 100,000 people.
The government is believed to be using a rate of 100 as the threshold above which quarantine measures are considered, a rate of 20 was previously being used.
There were concerns Germany, which currently has a rate of 107 cases per 100,000 people, would be added to the quarantine list. However, it remains on the exemption list.
Last week it was announced that travellers returning from The Maldives, Canary Islands, Mykonos and Denmark would not be required to self-isolate.