Countries across the globe shut their borders to Britain on Monday due to fears about the new strain.
"The government will take border control steps flexibly to prevent the spread of the coronavirus within the nation," Chief Cabinet Secretary Katsunobu Kato told a news conference.
"We request people to refrain from making short visits to the UK."
The government will ask people including long-term foreign residents to self-quarantine for 14 days upon return from Britain.
From next week, Japanese coming from Britain would be asked to submit a certificate to confirm they had tested negative for COVID-19 within 72 hours of their departure.
Kato also said that the government was gathering information and analyzing the impact from the coronavirus mutation in the UK and the UK-EU trade talks on Japanese companies.
