SINGAPORE: Leaders of the Southeast Asian nations will be in Tokyo on December 14 to celebrate another milestone in relations with Japan.
Political analysts expect a renewal of close ties between the countries during the ASEAN-Japan Commemorative Summit.
A key focus of discussions is likely to be the recent tensions in the East China Sea.
ASEAN and Japan's close relationship dates back to 1973.
It began with the establishment of the ASEAN-Japan forum on synthetic rubber.
Through the years, ASEAN and Japan have forged close cooperation on peace, stability, and development in Asia.
Observers said this year's ASEAN-Japan Commemorative Summit is timely.
Associate Professor Simon Tay, chairman of Singapore Institute of International Affairs, said: "Japan has been one of the key investors, and until recently (is) the top trader in ASEAN.
“Today, even when the Chinese economy is now bigger, Japan and ASEAN have more complementarity, a better fit, and this year particularly, ever since Abenomics has come in, many more Japanese companies are starting to look at Southeast Asia.
“And I think the summit has come in at a timely moment to try and deepen the relationship because in the past, people tend to look past Japan, but with Abenomics, now there is a certain reinforced optimism about Japan's place in the world."
However, the summit in Tokyo comes amid rising tensions in the East China Sea.
Last month, China declared a new Air Defence Identification Zone (ADIZ). This requires foreign planes to file their flight plans before flying through the zone.
It warns of "defensive emergency measures" if this is not adhered to.
Japan has called for the zone to be scrapped.
On Sunday, South Korea also announced that it is expanding its 62-year-old Air Defence Identification Zone in a clear reaction to China's new ADIZ.
And analysts expect this issue to be discussed during the summit.
Analysts also expressed concerns about the impact the ADIZ would have on commercial flights in the region.
They say the safest thing to do is for commercial aircraft to give the required notification.
Singapore has described the escalating situation over the East China Sea as a worrying development.
Foreign Affairs Minister K Shanmugam recently called for some degree of wisdom to prevail. He said the freedom of navigation and air rights are fundamental to Singapore.
Associate Professor Tay said: "ASEAN has two principles -- one is to remain united, and the second to be relatively neutral, a friend to all parties, including China which has also become a major partner for ASEAN in the last 15 years.
“And so we have to be friends with Japan without necessarily being dragged into its own bilateral interests."
Rodolfo Severino, head of ASEAN Studies Centre, said: "ASEAN countries are not so stupid as to take sides, because this thing affects the peace and stability of the region and ASEAN has a stake in it.
“Each ASEAN country has its own foreign policy, and it has to take into account its relationship with China, with Japan, with the United States."
And it is for this reason that analysts believe it will be unlikely that ASEAN will develop a common position on the issue.