Asian Games organisers are bracing for possible weather disruption in the opening few days of the multi-sports gathering with the possibility of a typhoon hitting the Aichi-Nagoya coast on Monday.

The 20th Asiad officially starts with the opening ceremony on Saturday but soccer, basketball and volleyball competitions are among those already underway in the region.

Tropical storm Dujuan was located off Japan's Pacific coast as of 0300 GMT on Thursday and heading northwest towards central Japan, where Nagoya is located. It was packing maximum sustained winds of 90 kph and gusts of up to 126 kph.

Torrential rains hit Nagoya and the surrounding region last week, leaving schools closed, train services suspended and forcing several hundred athletes to evacuate their accommodation.

Kosei Inoue, Japan's chef de mission for the Games and a senior executive board member of the Japanese Olympic Committee (JOC), addressed the weather threat at a news conference on Thursday.

"Due to the heavy rain and severe weather, some competitions have already experienced delays or postponements, and there is also a possibility that a typhoon could approach on September 21," he told reporters.

"Under these circumstances, we are holding thorough meetings within the JOC to ensure that we are fully prepared and capable of responding appropriately to these situations."