NHK has learned that adjustments are being made to include the importance of freedom of the seas around Africa in the declaration for Tokyo International Conference on African Development, or TICAD.
The Japan-led conference will run from August 28 to 30 in Yokohama, near Tokyo. The leaders of Japan and about 50 African countries will take part in the meeting, which is held every three years.
The Japanese government is seeking to issue the "Yokohama Declaration" at the end of the meeting.
A draft declaration shows it stresses the importance of freedom of the seas and the rule of law in the Atlantic Ocean, west of the African continent, in addition to the Indo-Pacific region.
Japan has stressed their importance in view of China's maritime advances.
China is increasing its influence in Africa through its support of infrastructure development in the region.
Observers say Japan is aiming to discuss investment by its companies in Africa and measures to protect the environment, areas in which Japan has expertise.
They also say Tokyo appears to be aiming to boost its presence in Africa by increasing the number of countries that support the importance of freedom of the seas.