Japan has expanded a state of emergency declared for the Tokyo area to seven more prefectures, with a senior government adviser adding it is uncertain whether the Olympics can go ahead due to the coronavirus pandemic.
Amid a steady rise in COVID-19 cases, the governors of Osaka, Kyoto and other hard-hit prefectures requested the government to announce the emergency, which gives local authorities the legal basis to place restrictions on residents' movements and businesses.
Prime Minister Yoshihide Suga has been wary about taking measures that would hamper economic activity, while he has put on a brave face against the mounting challenges of hosting the delayed Olympics in Tokyo this year.
Japan's coronavirus cases topped 300,000 on Wednesday, while the death toll reached 4,187, public broadcaster NHK said.
As infections hover at record levels, straining the country's medical system, opinion polls have shown a public increasingly opposed to holding the Summer Games and growing frustration with Suga.
In a weekend survey by NHK, just 16 per cent of respondents said the Games should go ahead - down 11 percentage points from the previous poll last month - while a combined 77 per cent thought the event should be cancelled or postponed.
The Games are set for July 23 to August 8.
But Takeshi Niinami, CEO of beverage giant Suntory Holdings and an economic adviser to Suga, told Reuters he was unsure whether the Olympics could be held as planned and that a decision will likely be made by end-March.
"I'm not sure whether we'll be able to hold the Tokyo Olympics or not," Niinami told Reuters in an online interview on Wednesday.
"But it's a great message to the world, as overcoming the battle against COVID. Definitely, we should make every effort."