Ministers from Japan and Southeast Asia agreed to complete a "roadmap" in August to double trade in 10 years between the world's third largest economy and the rapidly developing region.
The decision was made in Tokyo at a meeting of economic ministers from Japan and the 10 member states of the Association of Southeast Asian Nations (ASEAN), according to a joint press statement, released on Saturday.
The two sides had first agreed to work towards the plan when they met in August last year.
The roadmap will be presented for approval at a meeting of ASEAN and Japanese economic ministers in Cambodia in August, the statement said.
It will focus on areas such as liberalising trade, harmonisation of systems and narrowing development gaps.
"ASEAN is an important production base for our country and at the same time it is a market with remarkable growth," Yukio Edano, Japan's minister of economy, trade and industry, told a news conference.
"It is important for our country to join hands with ASEAN to seek economic growth."
Japan also backed ASEAN's proposed pact to encourage trade and investment, the Regional Comprehensive Economic Partnership (RCEP).
The pact is envisaged to involve 16 countries -- the ASEAN members and their "dialogue partners" -- Australia, China, India, New Zealand, Japan and South Korea -- with a total population of more than three billion.
The RCEP is not expected to require such rigid tariff-cutting rules as those under the Trans-Pacific Partnership (TPP) free trade agreement involving a number of countries including the United States, Kyodo news agency said.
ASEAN secretary general Surin Pitsuwan said the aim was to integrate ASEAN "into the global marketplace seamlessly without any obstacles."