Three prefectures neighboring Tokyo will jointly request the central government Thursday to add them to areas under the COVID-19 state of emergency after a recent surge in the number of coronavirus cases, Chiba Gov. Toshihito Kumagai said.

The governor expressed "a strong sense of crisis" over the rapid spread of the virus at a press conference. Yasutoshi Nishimura, minister in charge of Japan's COVID-19 response, said he will "swiftly decide and respond flexibly once the request is made" by Chiba, Kanagawa and Saitama prefectures.

Shigeru Omi, Japan's top coronavirus adviser, speaks during a parliamentary hearing in Tokyo on July 29, 2021. (Kyodo)

Japan's daily total of COVID-19 cases hit an all-time high of 9,583 on Wednesday, with Tokyo, already under a state of emergency through Aug. 22, confirming 3,177 COVID-19 cases. The three neighboring prefectures also reported record single-day highs.

The prefectures are currently under a quasi-state of emergency, which carries fewer restrictions on business activity than the state of emergency.

Shigeru Omi, Japan's top coronavirus adviser, urged the government in a parliamentary hearing Thursday to send out a strong message to people as he warned about the increased strain on the health care system.

"I have a strong sense of crisis. There are not many factors that will lower the current level of infections," said Omi, an infectious disease expert who heads the government subcommittee on the coronavirus.

He said the "greatest danger is in the fact that the general public does not share a sense of crisis," and that such a situation would lead to further spread of the virus.

"I want the government to send out a message that is clearer and stronger than ever without missing this timing," Omi said.

The surge in infections comes amid the spread of the highly contagious Delta variant of the coronavirus first detected in India. The number of people going out has not fallen, with the capital currently hosting the Olympics and many in Tokyo tired of restrictions under a state of emergency.