From then, Britain will be classified as extremely high risk and anyone staying in the UK for more than two hours will be unable to board passenger flights to Hong Kong.
The news will be greeted with dismay by airlines, which had only resumed flights in May after they were banned in December 2020.
British Airways and Virgin Atlantic were running limited services to the destination.
The Hong Kong government told Reuters the ban was due to "the recent rebound of the epidemic situation in the UK and the widespread Delta variant virus strain there, coupled with a number of cases with L452R mutant virus strains detected by tests from people arriving from the UK".
