The State Department's "Do Not Travel" advisory and guidance does not mention the Olympics and Paralympics specifically - but warned against visiting the country.

It was issued with the Olympic Opening Ceremony less than two months away on July 23.

"Because of the current situation in Japan, even fully vaccinated travellers may be at risk for getting and spreading COVID-19 variants," reads new guidance by the US Centers for Disease Control.

Japan's Olympic Minister Tamayo Marukawa attempted to play down the situation, with public opposition to Tokyo 2020 growing in Japan amid the coronavirus pandemic.

"At present, we can see no particular impact," she said in a press conference.

According to Reuters, Marukawa noted the advisory did not ban "essential" travel.

The United States Olympic and Paralympic Committee (USOPC) has planned mitigation practices which will allow for the safe participation of US athletes, she added.

Chief cabinet secretary Katsunobu Katō said Japan was in close contact with the US Government.

"There is absolutely no change in the United States' support for Japan's decision to hold the Olympics, we believe," said Katō.

A State Department spokesperson said that US President Joe Biden "proudly supports" the American athletes who have trained for the Games, while White House press secretary Jen Psaki said the Government's support for Japan staging the Olympics "has not changed".

The Tokyo 2020 Olympics are scheduled to run until August 8 after being pushed back a year due to the pandemic, despite the concerns from the Japanese public.

A petition called "Stop Tokyo Olympics" has reached more than 391,000 signatures to date.

 Japan has recorded more than 718,000 cases of COVID-19 in total, resulting in the deaths of more than 12,300 people.

Cases and deaths are falling from their peak earlier this month, but still remain high.

Yesterday, Japan recorded more than 4,000 new daily cases and 62 deaths.

Only 2.3 per cent of Japan's population has been fully vaccinated to date, a much slower rate than many countries.

All over 65s are expected to be fully vaccinated by the end of July.

International Olympic Committee (IOC) President Thomas Bach has attempted to ease concerns in the host nation, and said more than 80 per cent of people in the Tokyo 2020 Village will have been vaccinated.

The IOC could provide COVID-19 vaccines for 20,000 people in Japan who are set to compete or work at the Games, following a deal struck with Pfizer earlier this month. 

insidethegames has contacted the USOPC for comment.