TOKYO (Reuters) - A third passenger from the coronavirus-infected Diamond Princess cruise ship in Japan died on Sunday, authorities said, as the government promised to introduce fresh steps to contain the outbreak.

The latest death was a Japanese man in his 80s, the health ministry said on its website, days after a couple also in their 80s died.

The government is facing growing questions about whether it is doing enough to stop the spread of the virus, which originated in China and has killed more than 2,400 there. Tokyo is preparing to host the 2020 Summer Olympics in July.

Health Minister Katsunobu Kato said he would hold a meeting of experts on Monday and formulate a basic policy for addressing the disease on Tuesday.

Kato apologized on Saturday for allowing an infected woman to leave the Diamond Princess, which has been quarantined in Yokohama since Feb. 3.

The woman came ashore on Wednesday but then tested positive for the disease on Saturday in Tochigi Prefecture, north of Tokyo.

Kato said on Saturday that officials had failed to properly test 23 people who disembarked the ship, and his ministry was trying to contact them to be retested.

The ship is owned by Carnival Corp CCL.N and was originally carrying some 3,700 passengers and crew representing more than a dozen nationalities.

Some nations have flown their citizens home to undergo additional quarantines. Japanese authorities have allowed some other passengers to leave, prompting concerns they could be spreading the virus in Japan.

There have been 634 infections on the ship, according to national broadcaster NHK. Those cases represent the largest concentration of the illness outside China. [L4N2AL2U7]

Four new cases had been discovered in Japan as of early Sunday evening, bringing the total to 773, including the cruise ship, NHK reported.

The U.S. State Department raised its travel advisory for Japan to Level 2 on its four-notch scale on Saturday because of what it termed “sustained community spread.”