The head of the World Health Organization on Monday described the result of Japan's efforts in tackling the spread of the new coronavirus a "success."

WHO Director General Tedros Ghebreyesus made the assessment during a press conference in Geneva held in the wake of Japan's decision to lift a state of emergency in all parts of the nation after it was first declared in early April.

Tedros praised Japan for stemming the epidemic in recent weeks, reducing the spread of infections from more than 700 cases a day at the peak of the outbreak, and for keeping the number of deaths from COVID-19, the respiratory disease caused by the virus, at a relatively low level.

But he stressed at the same time that it is important for people in Japan to continue practicing social distancing and taking other basic precautionary measures, rules that apply to all countries when strict restrictions imposed to fight the virus are loosened.

Michael Ryan, the chief of the WHO's health emergencies department, said at the same press conference the world is still in the middle of the first wave of infections as the number of new cases is still increasing in African countries as well as Latin America and South Asia.

Ryan warned that a second wave could occur in countries that have eased stay-at-home and other restrictions.

On Monday, a Japanese advisory panel gave the go-ahead to the government's plan to end the emergency in Tokyo, its surrounding prefectures and Hokkaido, after determining such aspects as the number of newly reported cases over the past week and the availability of medical resources in those areas as satisfactory.

The areas were the last among Japan's 47 prefectures that were still covered by the state of emergency declaration and the accompanying voluntary restrictions that requested some types of businesses to shut temporarily and for people to stay home as much as possible.

Japan has avoided an explosive surge of COVID-19 infections with over 17,300 cases and 865 deaths reported across the nation as of Monday. The tally includes about 700 infections from the Diamond Princess cruise ship that was quarantined off Yokohama in February.

At the same press conference, the WHO said it is suspending its trial of hydroxychloroquine, a drug touted by U.S. President Donald Trump as a possible effective weapon in the battle against the virus, because of safety fears.

"The executive group has implemented a temporary pause of the hydroxychloroquine arm within the solidarity trial while the data is reviewed," Tedros said.

The WHO cited a study from medical journal The Lancet that "estimated a higher mortality rate" in patients that were administered the drug.

Trump claimed earlier in May he had used hydroxychloroquine to avoid contracting the coronavirus but said in a television interview on Sunday that he has "finished" taking the drug.

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