Japan's government is set to provide weather data to South Pacific islands to help them deal with disasters.

The announcement of the scheme will be made at the 10th summit of Pacific islands' leaders scheduled from July 16 to 18 in Tokyo.

Since 1997, Japan has invited South Pacific leaders to the summit once every three years. Eighteen leaders are scheduled to attend this year's meeting, and Prime Minister Kishida Fumio will be co-chair.

Kishida is set to announce that Tokyo will provide data held by the Japan Meteorological Agency. The information will be used for evacuation and other measures in the event of disasters such as cyclones and tsunami.

It will be provided in real time using the Michibiki satellite, a Japanese-version of a global positioning system.

The data will be given to Fiji first as an experimental project.

China has been exercising more influence over the South Pacific in recent years through infrastructure projects.

Japan plans to strengthen ties with the countries in the region by supporting their disaster countermeasures on top of many years of official development assistance.

The prime minister is also expected to explain the discharge of treated water from the crippled Fukushima Daiichi nuclear power plant and call for understanding of its safety.

The Fukushima Daiichi plant suffered a triple meltdown in the 2011 earthquake and tsunami.

Water used to cool molten fuel has been mixing with rain and groundwater. The accumulated water is being treated to remove most radioactive substances, but still contains tritium.

Before releasing the treated water into the ocean, the plant's operator dilutes it to reduce the tritium levels to about one-seventh of the World Health Organization's guidance level for drinking water.