Japan is not a member of Asean, but if the project materialises, it - along with South Korea, China, India, Australia and New Zealand - would be part of Asean, which includes Singapore, Malaysia, Indonesia, Thailand and Vietnam.
Other Asean member states are Brunei Darussalam, Burma, Cambodia, the Philippines and Cambodia.
"It's not just Asia coming together economically but politically as well. The more integrated you are, the more forceful you are"
Head of the Singapore-based Asean Studies Centre
Severino said a more cohesive Asia would have a bigger role in global affairs, especially after the region overcame the global economic crisis more quickly than the West.
"It's not just Asia coming together economically but politically as well. The more integrated you are, the more forceful you are," Severino said.
He currently heads the Singapore-based Asean Studies Centre.
Kasit Piromya, the Thai foreign minister, said a separate study on a wider grouping that would take in India, Australia and New Zealand, would be carried out in tandem, and that the two could be combined to create "one regional co-operation on a larger scale".
Asean is already committed to setting up a single Southeast Asian free trade zone by 2015, creating a bloc with a total GDP of more than $1 trillion.
Reporting from Hua Hin, Al Jazeera's Step Vaessen said: "Before you have this economic market, you have, of course, to be connected - and that's one of the topics that has been discussed here - connectivity within the region.
"China has already pledged $10bn to improve that because there is still a lot of work to be done there."
'Difference in income'
Asean still has major issues to resolve given its diverse membership, our correspondent said.
"There's a huge difference in income between the countries. Singapore is the richest with a GDP a hundred and fifty times higher than Myanmar, the poorest in the bloc," she said.
"Politically, the differences are even more diverse," Vaessen said.
"You have democracies, you have mornachies, you have all kinds of different regimes in the region and it's very difficult to find some kind of common ground."
Analysts said East Asian community remains a long way off, largely due to the lack of concrete proposals and disagreements about the involvement of the US and the influence of China.
Japan and some other countries want to give Washington a role in the group, as a counterbalance to the influence China might have on a new regional architecture.