The Japanese government hopes to play a role in the development of a regional logistics hub in southeastern Iran, according to sources.
Japan hopes to team up with India on the construction of the site, which is set to include a port and an industrial complex. India has already begun work on the plan.
With Iran expected to enter a period of growth after the lifting of economic sanctions last year, Tokyo is keen to build stronger ties with Tehran.
Japanese Prime Minister Shinzo Abe hopes to reach a deal during a planned visit to the Iranian capital later this year.
The planned site for development is the city of Chabahar on the coast of the Gulf of Oman, close to the Pakistani border. The location lies in Iran's southernmost free trade zone and offers prime access to shipping lanes in the Indian Ocean. It is also a pivotal trade hub for Afghanistan and other Central Asian countries.
In April, the Indian government announced plans to invest some $20 billion to build fertilizer and petrochemical plants at Chabahar.
The Japanese government hopes to start drawing up specific plans by the end of this year through the Japan International Cooperation Agency. Taking heed of requests from Iran and India, the government will decide on details such as the necessary infrastructure and a list of companies it will invite to tender for the project. The investment will use official development assistance.
The Japanese government hopes to develop the area into a trading center for resource-rich Central Asian countries such as Turkmenistan, the world's fourth largest producer of natural gas. It also hopes that Chabahar will serve as a logistics pivot for Iran and Afghanistan.