FILE PHOTO: Japan's Prime Minister Shinzo Abe wears a protective face mask as he attends an upper house parliamentary session, following an outbreak of the coronavirus disease (COVID-19), in Tokyo, Japan April 1, 2020. REUTERS/Issei Kato

TOKYO (Reuters) - The Japanese government is considering a period of six months for the state of emergency that it is preparing to call in response to the coronavirus pandemic, broadcaster TBS reported on Monday.

The move would cover Tokyo and three neighbouring prefectures as well as Osaka, TBS said, citing unidentified sources. Within the six-month period, these prefectures would decide the length of time for their individual measures, TBS said.

The government is preparing to announce a state of emergency as early as Tuesday, the broadcaster said.