A strong typhoon is forecast to approach western and eastern Japan from Tuesday through Wednesday, with shinkansen bullet train operators warning of potential suspensions of services in many areas as a precautionary measure.

In a statement carried by Kyodo News, the Japan Meteorological Agency said Typhoon Shanshan is expected to move north toward the Japanese Pacific coast while strengthening in force due to high sea temperatures, although its path is still hard to predict.

As of 9:00 JST Saturday, the typhoon was located around the Ogasawara Islands, south of Tokyo, moving northward at a speed of 25 kilometres per hour.

The agency also warned of lightning, gusts, hail and torrential rain over the weekend ahead of the tropical storm's arrival, as the weather is likely to be unstable with warm air coming through the edge of a high-pressure system.

Torrential rains have frequently hit Tokyo and its surrounding areas recently, flooding roads and affecting train services.