China expressed on Tuesday it is waiting for an official word on why Japan plans to send its largest warship on a three-month tour through the South China Sea.

China claims almost all the disputed waters and its growing military presence has fuelled concern in Japan and the west.

The Izumo helicopter carrier, commissioned only two years ago, will make stops in Singapore, Indonesia, The Philippines and Sri Lanka before joining the Malabar joint naval exercise in the Indian ocean in July.

Chinese Foreign Ministry Spokeswoman Hua Chunying said she did not know if the ship was going to visit countries in Southeast Asia or if there was another aim.

Taiwan, Malaysia, Vietnam, The Philippines and Brunei also claim parts of the sea which has rich fishing grounds, oil and gas deposits and through which around $5 trillion of global sea-borne trade passes each year.

Tags: China, Japanese warship, South China Sea