Tokyo's Olympics chief says that Japan is committed to holding a safe Games as a surge in COVID-19 cases prompted an expansion of contagion controls and with fresh calls for the Games to again be postponed or cancelled.
The government expanded quasi-emergency measures to 10 regions as a fourth wave of infections spread, casting more doubt on whether the Olympics can be held in Tokyo in fewer than 100 days.
"We're not thinking of cancelling the Olympics," Tokyo 2020 President Seiko Hashimoto said, speaking on behalf of the organising committee.
"We will continue to do what we can to implement a thorough safety regimen that will make people feel complete safety."
The government added Aichi, Kanagawa, Saitama, and Chiba to six other prefectures already under contagion controls, including the cities of Tokyo and Osaka.
Japan's top health experts have acknowledged that the COVID-19 pandemic has entered a fourth wave.
Almost two-thirds of Japanese said the Olympics should be cancelled or postponed, a Jiji news poll showed on Friday.
A senior ruling party official said on Thursday that cancelling this year's Olympics remains an option if the coronavirus situation becomes too dire.
A scaled-back torch relay is already underway. Overseas fans have been barred from the Games and officials say that domestic fans may be kept out too.
Underscoring the difficulties of planning during the pandemic, Tokyo Olympic organisers postponed another test event, the BMX freestyle cycling scheduled for April 24-25, because of the impact on scheduling from the COVID-19 situation.
Olympic and government officials have said further postponement of the Games is out of the question.
But a groundswell of health experts have said it's too risky to hold the Games this summer.
Compounding the problem is Japan's relatively slow inoculation push, which began February using imported vaccines.
Japan has exhibited "poor performance" in containing virus transmission, along with limited testing capacity and a slow vaccination rollout, according to a commentary of health experts published in the British Medical Journal on Wednesday.
"Plans to hold the Olympic and Paralympic games this summer must be reconsidered as a matter of urgency," wrote lead author Kazuki Shimizu of the London School of Economics.
"Holding Tokyo 2020 for domestic political and economic purposes--ignoring scientific and moral imperatives--is contradictory to Japan's commitment to global health and human security."