Japan has extended a COVID-19 state of emergency in Tokyo and nine other regions for another three weeks.
Prime Minister Yoshihide Suga said that although infection were falling they remained high, and that some hospitals were still under strain
Restriction will be in place until 19 June, five weeks before the postponed Tokyo 2020 Olympics are due to start.
Organisers said they would wait until the emergency ends on 20 June to decide whether to allow local fans to attend.
Overseas fans have already been barred.
Experts said the daily infection rate in Tokyo has to fall below 100 in order for the city to safely host the Games. On Thursday, there were almost 700 new infections in the capital.
Mr Suga said hospitals were still overwhelmed in some regions, such as Osaka.
"The next three weeks are an extremely important period in achieving results in infection prevention and vaccine inoculation, a two-pronged strategy," he added.
"From the bottom of my heart, I ask for everyone's understanding and co-operation."