TOKYO — A surge in coronavirus cases has put "real pressure" on Japan to cancel this summer's Olympics, Australia's Prime Minister Scott Morrison said Friday, as a report suggested the mood within Japan's ruling coalition had turned against holding the Games despite public assurances to the contrary.

Japan is in the grip of its most serious coronavirus wave, and Tokyo is under a state of emergency. The government has not approved a vaccine for use here, let alone begun inoculating people. Still, the country's leader and Olympics organizers say the Games are going ahead.

“I am determined to realize a safe and secure Tokyo Games as proof that mankind will have overcome the virus,” Prime Minister Yoshihide Suga told parliament on Friday, as ministers and senior officials denied a report in the Times of London suggesting his government privately acknowledges the Games may have to be called off.

Olympics Minister Seiko Hashimoto said at a news conference that many sports events were already taking place globally amid pandemic precautions. Preparation for a successful Games would continue, she said, “to bring hope to people all over the world.”

A statement from the International Olympic Committee said organizers are “fully concentrated on and committed to the successful delivery of the Olympic and Paralympic Games Tokyo 2020 this year.”

But Morrison’s comments reflected a more cautious, and perhaps realistic, assessment of the situation. The Australian leader’s remarks are significant because last year, the decision to postpone the Tokyo 2020 Games came shortly after Australia and Canada announced they were withdrawing their athletes because of the coronavirus pandemic.

“The situation in Japan right now in terms of the spread that’s occurred there more recently, is quite different to even when I was there in November,” Morrison said at a news conference, adding that Suga had to put the health and safety of his people first.

Morrison’s comments give Suga greater room to recommend cancellation, but for now the head of Australia’s Olympic Committee is still determined to see his team there.

“The Tokyo Games are definitely on. The flame will be lit on the 23rd of July,” Australian Olympic Committee chief Matt Carroll said in Sydney, according to media reports.

Last year, as the pandemic spread, the IOC quietly pushed then-Prime Minister Shinzo Abe to accept that there was no choice but to postpone the 2020 Games until this year.

This time, without Abe at the helm, Tokyo’s determination to push ahead seems less firm.

On Tuesday, Japan’s daily covid-19 death toll topped 100 for the first time. Although that’s a fraction of the numbers in the United States, hospitals in Tokyo are turning away patients. The thought of large numbers of foreigners entering Japan for the Games is not something this island nation relishes.

Senior government minister Taro Kono opened the first crack in the optimistic facade when he told Reuters last week that a decision on whether to hold the Games “could go either way.” This week, a senior official from Japan’s ruling coalition told the Times newspaper that Japan was now focusing on finding a face-saving way out, by securing the next available date to host the Games — in 2032.

“No one wants to be the first to say so, but the consensus is that it’s too difficult,” the unnamed official was quoted as saying. “Personally, I don’t think it’s going to happen.”

The unnamed official said Suga was “not emotionally invested” in the Games. Certainly hosting the Olympics was his predecessor’s dream, and not Suga’s.

In Japan’s parliament, or Diet, opposition leaders this week expressed their concerns or called outright for the Games to be called off.

“It is becoming difficult to hold the Games,” said Yuichiro Tamaki, head of the opposition Democratic Party for the People, according to local media. “Looking at the discussions in the Diet today, I felt that there was no motivation and felt as if they had given up.”

Yet the people closest to the Games insist it can be done. Lessons have been learned from sports events taking place elsewhere, and meticulous preparations are being drawn up.

“We have, at this moment, no reason whatsoever to believe that the Olympic Games in Tokyo will not open on the 23rd of July in the Olympic Stadium in Tokyo,” IOC President Thomas Bach said in an online interview with Kyodo News this week. “This is why there is no Plan B and this is why we are fully committed to make these Games safe and successful.”

In Japan, a poll by Kyodo News this month found 35 percent of respondents favored a cancellation and 45 percent preferred another postponement — although Tokyo 2020 organizers insist the latter is not an option.

But Tokyo 2020 spokesman Masa Takaya noted that only 17 percent of allocated tickets were returned when ticket-holders were given a chance to apply for refunds in November, while most volunteers remained enthusiastic when surveyed by the organizers last year, he said.

“We are living in a world of uncertainty right now,” Takaya acknowledged, adding that this made it even more important for Tokyo 2020 to devote “100 percent focus” on how to organize and deliver the Olympics.

“We hope that daily life can return to normal as soon as possible, and we will continue to make every effort to prepare for a safe and secure Games.”

Julia Mio Inuma contributed to this report.