The Japanese government will ban entry to most foreigners through the end of January as coronavirus cases reach record highs there and the nation confirmed its first cases of the new, more infectious Covid strain.

The restrictions will be implemented on Monday, the government said in a statement. Japanese nationals and foreigners with residency who are returning from short business trips will no longer be exempt from 14-day quarantine, according to Saturday’s statement.

The move comes amid mounting concerns over the spread of a new variant of the virus at a time when cases in Tokyo have reached new highs. The variant, which emerged in southeast England in September and is spreading rapidly in the U.K., is much more infectious than previous strains. Germany, France, Switzerland, Ireland and Sweden are among the nations that have confirmed the presence of the new variant.

On Saturday, Japan’s capital reported a record 949 new cases, with reports saying two more people, in addition to five confirmed on Friday, were found to be infected with the new strain. Governor Yuriko Koike said the New Year’s holiday period would be “a very important juncture” that would predict the future of Tokyo in 2021, and asked residents to avoid going out during the holidays.

Japan’s travel restrictions follow steps taken by other countries in their efforts to curb the spread of the virus, with early analysis suggesting the new variant may be as much as 70% more transmissible than other circulating strains.

The U.S. will require passengers flying from the U.K. to show proof of a negative test for coronavirus starting Dec. 28, while regions from Hong Kong to Canada have temporarily suspended travel from the U.K.