The UK is to close all travel corridors from Monday morning to “protect against the risk of as yet unidentified new strains” of Covid, said UK Prime Minister Boris Johnson.
The new rules would be in place until at least 15 February, he added.
All travel corridors will close from 04 am local time on Monday. After that, arrivals to the UK will need to quarantine for up to 10 days, unless they test negative after five days, he further said.
The rules would apply across the UK after talks with the devolved administrations, added that the government would be stepping up enforcement at the border.
It comes as a ban on travellers from South America and Portugal came into force on Friday over concerns about a new variant identified in Brazil.