A fourth person has died in Japan after becoming ill aboard a coronavirus-stricken cruise ship, local media reported Tuesday, as the government unveiled a new policy to tackle the outbreak.

Nearly 700 people on board the Diamond Princess, which spent two weeks quarantined off Japan, have so far tested positive for the virus.

Four people who were hospitalised after being taken off the ship have died, the latest a man in his 80s, according to local media.

The Yomiuri Shimbun daily said the man had tested positive for the new coronavirus and died of pneumonia. The health ministry did not immediately respond to a request for comment on the reports.

Three others, all Japanese, have so far died after becoming sick on the ship. Two were confirmed to have the new coronavirus, while the health ministry declined to comment on the diagnosis of the third.

Japan has come under increasing pressure over its handling of the ship Japan has come under increasing pressure over its handling of the ship Photo: AFP / Kazuhiro NOGI

Japan has come under increasing pressure over its handling of the ship, particularly after it emerged that some passengers allowed to disembark after testing negative were subsequently diagnosed with the virus.

Some of the disembarking passengers were not even tested during the quarantine period, the health ministry has acknowledged.

Several government officials working on the ship have themselves contracted the infection, but authorities have defended a policy of not uniformly testing those working on the boat.

"We are aware of the risks of them getting infected when they take off a mask or gloves, so we will have thorough measures to prevent infections under these circumstances," Health Minister Katsunobu Kato said, while stressing no change in policy was planned.

Many nations have evacuated their citizens from the ship, with 450 Filipinos due to be flown home on Tuesday on two chartered flights. Another 81 who have tested positive for the virus will stay in Japan.

The Japanese health minister has urged people to avoid crowds and unnecessary gatherings The Japanese health minister has urged people to avoid crowds and unnecessary gatherings Photo: AFP / CHARLY TRIBALLEAU

As the situation on the ship has come under scrutiny, infections have spiked inside Japan, with 156 cases including one death.

"As we see patients whose infection routes are not clear in several regions in Japan, now is a crucial phase to prevent the spread of infection from happening on a huge scale," government spokesman Yoshihide Suga told reporters on Tuesday.

"It is important that we contain the spread in Japan by slowing the speed of the increase of new patients as much as possible," Prime Minister Shinzo Abe said at a cabinet meeting on the outbreak.

"To this end, we shall thoroughly strengthen measures against patient clusters."

The government is expected to take measures including expanding the number of hospitals that can receive suspected patients, as well as asking people with moderate symptoms to stay at home.

The health minister has already urged people to avoid crowds and unnecessary gatherings, and the government has called for businesses to encourage teleworking and off-peak commuting.

On Tuesday, the J-League said it was cancelling football cup games scheduled for Wednesday over the virus, but the government has brushed aside worries about the Olympics, which Tokyo hosts this summer.

"We are talking about the situation now," Kato said when asked about the Games on Tuesday.

The Tokyo Olympics "is taking place in July, so we are not talking about that situation... we are talking about the government's position now".