US health officials and the State Department have warned Americans against travelling to Japan because the country, which is preparing to host the Olympics in just two months, is still battling the latest surge of coronavirus cases.

The twin alerts don’t ban US citizens from visiting Japan, but they could have an impact on insurance rates for travellers and may impact decisions by Olympic athletes and spectators about whether to compete in or attend the games, which are due to start in July.

“Travellers should avoid all travel to Japan,” the Atlanta-based Centres for Disease Control and Prevention said in a new COVID-19 update.

“Because of the current situation in Japan, even fully vaccinated travellers may be at risk for getting and spreading COVID-19 variants and should avoid all travel to Japan.”

The State Department’s warning, which followed the CDC alert, was more blunt, stating: “Do not travel to Japan due to COVID-19.”

It raised the travel alert from Level 3 – reconsider travel – to Level 4 – do not travel.

The United States Olympic and Paralympic Committee (USOPC) said it still anticipated American athletes would be able to safely compete at the Tokyo Games.

“We feel confident that the current mitigation practices in place for athletes and staff by both the USOPC and the Tokyo Organising Committee, coupled with the testing before travel, on arrival in Japan, and during Games time, will allow for safe participation of Team USA athletes this summer,” the committee said in a statement Monday.

Earlier on Monday, Japan mobilised military doctors and nurses to inoculate older adults in two major cities, as the government tried desperately to accelerate its vaccination rollout and curb coronavirus infections.

That move came amid growing calls for the games to be cancelled.

However, Japanese Prime Minister Yoshihide Suga is determined to hold the Olympics in Tokyo from July 23, after a one-year delay because of the pandemic.

He has made an ambitious pledge to finish vaccinating the country’s 36 million older people by the end of July.

Japan has recorded just over 12,000 COVID-19 deaths, which is low by global standards, but high when compared to many other countries in Asia.

Tokyo, Osaka and several other areas are still under a state of emergency until May 31, and that is likely to be extended.

There is fear of new variants spreading, with only a tiny number of Japanese people – estimated at 2 to 4 per cent – vaccinated.

-ABC