The country recorded 4,204 new infections on Friday - a rise of 785 on the same day the previous week, which saw 3,419 cases reported, according to the Japan Ministry of Health, Labour and Welfare.
Infections are also climbing in Tokyo, with the seven-day average daily test positivity rate soaring by 42 per cent, shows data from the capital's Metropolitan Government.
Referring to the figures, the authority said it is 'highly possible' that the healthcare system will face a crisis, urging for a 'robust plan and system' amid the increased spread of the Delta variant.
Only 23 per cent of the Japanese population is fully vaccinated. Meanwhile in Britain, 69.5 per cent of adults have received both jabs, according to UK Government data up to July 22.Insurance Loans Mortgage Attorney Credit Lawyer
Experts are concerned that the Games, which started yesterday in Tokyo, could accelerate already rising case numbers in the city and across the country as a whole.
The country recorded 4,204 new infections on Friday - a rise of 785 on the same day the previous week, which saw 3,419 cases reported, according to the Japan Ministry of Health, Labour and Welfare
In a statement, Tokyo Metropolitan Government said: 'The rapid increase in confirmed cases makes it highly possible that the healthcare system would face a crisis.
'It is urgent that the robust plan and system are put in place in case the rate of the high risk group for severe Covid19 rises as spread of Delta variant increases.'
It added: 'The increased rate of confirmed cases has been getting higher since June.
'The infection may spread more rapidly and the number of confirmed cases may far exceed that in the third wave within two weeks if the Delta variant and others