Japan is to require Olympic athletes and others coming from eleven countries, including Britain, to be Pre-tested daily for the coronavirus for between three and seven days prior to departure.
The measure will take effect on Thursday 1 July 2021.
NHK-World Media reports that the measure applies for three days prior to departure for athletes from Britain, Egypt, Vietnam, Malaysia, and Bangladesh.
And for seven days for athletes from India, Nepal, Pakistan, Maldives, Sri Lanka and Afghanistan, where the Delta variant is spreading.
The highly contagious variant was first identified in India.
The Japanese government and the Tokyo Olympic organizing committee have already asked all foreign teams to have members tested twice within four days prior to departure, and every day in principle after arriving in Japan.
Athletes will be allowed to practice, provided they do not come into contact with others not on their teams for three days after arriving in Japan.
Members of the British Sailing team are expected to leave for Tokyo in early July.