Japan will make good use of the aid it gives developing countries to promote its "Free and Open Indo-Pacific Strategy," the government said in its 2017 white paper on official development assistance.
The report on ODA, approved by the Cabinet on Friday, said Tokyo wants the vast region to serve the "international public good," and to that end will support developing countries in reinforcing maritime law enforcement.
"A free and open maritime order based on the rule of law is a cornerstone for peace and prosperity in the international community," the paper said.
The concept is being pushed by Prime Minister Shinzo Abe as a way to bring more stability to a region stretching from East Asia to Africa.
Amid China's rise, Abe says Japan should strengthen cooperation with other countries to ensure the fast-growing region is built on democracy, rule-based order and market mechanisms.
Through its ODA, Tokyo will also try to develop "high-quality" infrastructure in the Indo-Pacific region to encourage the flow of people and goods, the report said.
A key to stability and prosperity in the international community is the dynamism that is created by combining Asia and Africa and the Pacific and Indian oceans, the paper said.
Elsewhere, it said Japan will take the lead in promoting United Nations sustainable development goals.
In December, Abe said Japan will contribute about $2.9 billion to programs providing universal health coverage. Such programs are designed to help all people and communities in the world use basic health services without facing financial hardships.
Universal heath coverage is one of the sustainable development goals that U.N. members are trying to achieve by 2030.
In 2016, Japan distributed $16.8 billion in ODA, placing it fourth among members of the Organisation for Economic Co-operation and Development after the United States, Germany and Britain, according to the paper.