Tokyo, Sep 17 (IANS): Japan's weather agency said on Tuesday that a large tropical storm that is gaining strength may approach Okinawa prefecture and Amami region of Kagoshima prefecture in Japan on Wednesday.

As of 6 A.M. local time, tropical storm Pulasan was over waters near the Mariana Islands in the Pacific Ocean and was moving northwest at a speed of 30 km per hour (KMPH), the Japan Meteorological Agency reported.

The typhoon may come closest to Okinawa prefecture and the Amami region of Kagoshima prefecture on Wednesday, Xinhua news agency reported.

Winds of up to 54 KMPH are expected in the Okinawa region on Tuesday, with peak gusts of 90 KMPH, it added.

In the 24 hours until Wednesday morning, up to 50 millimetres of rainfall is expected in the Okinawa region. Rainfall could also reach 150 millimetres in the Amami region and 100 millimetres in the Okinawa region in the 24 hours until Thursday morning, according to the agency.

Weather officials said that rough seas are expected in those regions through Thursday, urging people to be on alert for high waves, strong winds, storm surges, landslides and flooding in low-lying areas.