Japan aims to dispatch its largest warship on a three-month tour through the South China Sea beginning in May.
This is the biggest show of naval force in the region since World War Two.
China claims almost all the disputed waters and its growing military presence has fuelled concern in Japan and the West.
The United States has been holding regular air and naval patrols to ensure freedom of navigation.
The Izumo helicopter carrier will make stops in Singapore, Indonesia, the Philippines and Sri Lanka before joining the Malabar joint naval exercise with Indian and US naval vessels in the Indian Ocean in July.
It will return to Japan in August.
Taiwan, Malaysia, Vietnam, the Philippines and Brunei also claim parts of the South China sea which has rich fishing grounds, oil and gas deposits and through which around $5 trillion of global sea-borne trade passes each year.
Japan does not have any claim to the waters, but has a separate maritime dispute with China in the East China Sea.
Izumo: Know More- The 249 metre-long (816.93 ft) Izumo is as large as Japan's World War Two-era carriers.
- It can operate up to nine helicopters.
- It resembles the amphibious assault carriers used by US Marines.
- It lacks their well deck for launching landing craft and other vessels.
- Based in Yokosuka, near to Tokyo, which is also home to the US Seventh Fleet's carrier, the Ronald Reagan, the Izumo's primary mission is anti-submarine warfare.
