Japan's health minister Kato Katsunobu has hinted at the possibility of another nationwide state of emergency if infections of the novel coronavirus surge.

Kato told reporters on Tuesday that he is aware local authorities are taking measures to contain infections. But he said the government could declare another state of emergency if the number of cases rises rapidly despite such efforts.

Okinawa Prefecture has declared its own state of emergency while other municipalities have requested people to refrain from nonessential outings and businesses to shorten hours.

Kato said that in the case of another state of emergency, the government will reach a comprehensive decision on it after looking at various indicators and hearing experts' views. He said the government will keep a close eye on the trend of infections and extend aid such as an enhanced testing system when necessary.