The spirit of enhancing regional cooperation has been highlighted and upheld by leaders attending the 16th Association of Southeast Asian Nations (ASEAN) Plus Three Summit (APT), with analysts stating their optimism over easing tensions between APT's key players.

Since the Asian financial crisis in 1997, the APT, which comprises all 10 ASEAN members together with China, South Korea and Japan, upheld aims of ensuring economic recovery, financial stability and deepening links amongst the countries to promote regional economic cooperation.

Brunei's Sultan Hassanal Bolkah said at the summit that these principles have helped strengthen regional cooperation towards building an East Asia Community.

In 2011, China's total trade volume with ASEAN, Japan and South Korea accounted for 26 percent of China's total trade volume that reached about 3.6 trillion U.S. dollars, showing that the multilateral regime has brought concrete benefits to its participants.

Also during the summit, Chinese Premier Li Keqiang highly praised the APT and said it has played an important role in stabilizing the East Asian economy and made a significant contribution to the economic growth of the region and the world at large.

Meanwhile, Japanese Prime Minister Shinzo Abe said that the mechanism is an important framework for regional cooperation, and along with Japan-China-ROK trilateral cooperation and the East Asia Summit, he hoped for further development of regional cooperation.

In fact, the APT has already become a major channel in contributing to the East Asian cooperation. "Spanning economic, political, infrastructural, educational, environmental and -- sometimes overlooked -- cultural areas, the APT framework is essential to the development of the East Asian region," Laurent Sinclair, a Pacific affairs research analyst, told Xinhua in a recent interview.

He said that the unique APT paradigm aims to provide a regular platform for ongoing discussions on the key issues, with a goal towards enhancing the region and forging closer ties between them.

Brunei's sultan also highlighted the fact that trade and investment amongst the APT countries has continued to grow against the backdrop of current international economic woes, adding that theses facts underscored the importance and significance of continuing to advance regional cooperation.

With a background of ongoing negotiations of a trilateral free trade area among the three northeast Asian countries, ASEAN has gone further and has initiated a framework of "Regional Comprehensive Economic Partnership (RCEP)," with relevant talks already underway.

Hassanal appealed to the three northeast Asian countries for a timely and successful conclusion of the RCEP, which analysts said, among other cooperative mechanisms in the East Asian region and even in the entire Asia-Pacific region, will be the most operable one that will better meet regional realities.

However, along with the spirit of cooperation that was agreed by all leaders from the APT members, there are a number of unique challenges that have presented themselves and need to be addressed by stages in the near future, said Sinclair.

"On the economic front, more needs to be done to facilitate the development of smaller, emerging nations for the benefit of the entire region. Lending facilities, for example, need to be enhanced for infrastructural development and technical know-how needs to be exchanged more freely," the analyst said.

He went on to say that other issues that are putting a stain on the effectiveness of the framework are ongoing strained relations between some key players. "Whether or not these are at the forefront of ASEAN discussions is irrelevant, the point is that simmering issues have a knock-on effect on other countries."

"If the relationships between the three largest powerhouses can be improved through enhanced diplomacy, then this would have a positive affect on all aspects within the ASEAN framework and boost the prosperity and progress in the region and among its member countries," said Philip McNeil, a writer and commentator on Japanese socio-political issues.

He maintained, however, that it is not a simple task, but steps forward must be taken even if each respective country has to make some concessions -- it's all about diplomacy after all -- as strategic as these may be.

Similarly, Kaoru Imori, a commentator on Japanese affairs, also showed his optimism by saying that the diplomatic ties in Northeast Asia will return to normal, but it will be a strategic and gradual process.

He said the three countries all have new leaderships and they are reliant on each other economically.

"It may be too early for these ASEAN summits, but I believe some groundwork will be laid on the sidelines as bilateral and trilateral cooperation between the three nations is indispensable for the region," said the renown analyst.