A team of US environmental experts has surveyed an area of northeastern Japan that was struck by a massive earthquake and tsunami on March 11 2011.

On Tuesday, a team from the Smithsonian Environmental Research Center visited a lagoon in Rikuzentakata City in Iwate Prefecture. The lagoon was connected to the sea after a massive tsunami.

Japan's health ministry says 88 more people on board the quarantined cruise ship Diamond Princess have tested positive for the new coronavirus. Sixty five of them have not developed any symptoms.

The number of infections on the ship anchored at Yokohama Port, near Tokyo, has now risen to 542.

A Japanese doctor at a national research institute says he hopes that an HIV drug that is being tested to treat people infected with the new coronavirus will be approved for clinical use as soon as possible.

Norio Ohmagari, the director of the Disease Control and Prevention Center in Tokyo, says the anti-AIDS drug is being used on a trial basis at medical institutions in many countries. He points out that the drug was used overseas to treat SARS and MERS patients in the past.

The Japanese government's hotline for foreign tourists has been flooded with inquiries about the new coronavirus.

The Japan Visitor Hotline operated by the Japan National Tourism Organization offers support in English, Chinese and Korean 24 hours a day.

Japanese health officials say three more people have tested positive for the new coronavirus in the western prefecture of Wakayama.

One of them is under the age of 20, and is the youngest case in Japan so far.

Japan's health minister says people on board the Diamond Princess who test negative for the new coronavirus will be able to leave the quarantined cruise ship from Wednesday.

Katsunobu Kato told reporters on Tuesday morning that throat swabs of all passengers have been collected as of Monday and lab test results will be available by Wednesday.

Chief Cabinet Secretary Yoshihide Suga says Chinese President Xi Jinping's state visit to Japan is expected to take place in April as planned.

Suga told reporters on Tuesday that Japan is closely watching developments concerning China's National People's Congress.

Britain has urged Japan to raise its reduction target for greenhouse gas emissions ahead of a UN climate change conference later this year.

All members of the Paris Agreement are required to submit their new reduction targets to the United Nations by the end of this month.

Japan's Cabinet has approved a bill to support domestic firms investing in 5G communication networks and drones. Commercial 5G services are scheduled to start in Japan this spring.

The approval came at a Cabinet meeting on Tuesday.

Japan is expected to become capable of testing up to about 3,800 people a day for the coronavirus on Tuesday, as it is working to boost its testing capabilities.

The health ministry told municipalities across Japan to expand the scope of their screenings to include people with suspected infections who have had no travel history to the Chinese provinces of Hubei or Zhejiang.

The World Health Organization says it is working closely with Japanese authorities and medical officers of the Diamond Princess to respond to coronavirus infections.

More than 450 people on board the cruise ship docked at Yokohama Port have been confirmed to have the virus.

Lawmakers of Japan's opposition camp have questioned Prime Minister Shinzo Abe regarding parties that were held for his supporters at a Tokyo hotel over the past several years.

At the Lower House budget committee meeting on Monday, opposition lawmakers said they asked a Tokyo hotel whether it had made out receipts for the parties with no customer names. They said the hotel, where some of the parties were held, replied that it had not.

Japan's health ministry says 99 more people on board the quarantined cruise ship Diamond Princess have tested positive for the new coronavirus.

The ministry said on Monday that of the newly found virus carriers, 85 are passengers and 14 are crewmembers.

Japan's Imperial Household Agency has canceled Emperor Naruhito's greetings to the public on his birthday on February 23 due to the new coronavirus outbreak.

The occasion would have marked the emperor's first birthday greeting since he ascended to the throne last May.