The Asean Foreign Ministers will hold talks till Saturday and will also meet US Secretary of State Mike Pompeo, Chinese Foreign Minister Wang Yi and his Russian counterpart Sergey Lavrov as well as those of Australia, New Zealand, Japan, Peru and the EU.
Britain's newly appointed Foreign Secretary, Dominic Raab, will seek new business opportunities in Thailand - which this year holds the rotating chair of the bloc - and strengthen diplomatic ties amid the UK's exit from the EU.
In his keynote address, Thai Prime Minister Prayut Chan-ocha highlighted cooperation and dialogue with foreign allies to achieve sustainable development and regional security through trust, respect and mutual understanding.
Thai Foreign Minister Don Pramudwinai also stressed the role of the Asean bloc to lead challenges such as the fight against climate change, growing trade competition among regional powers and the rise of nationalism, Efe news reported.
The statements of Pompeo and Yi, who will meet on Friday during the East Asia Forum, will garner much of the summit's attention within the context of the rivalry between Washington and Beijing, in particular the ongoing trade war, the effects of which are beginning to be felt in the global economy.
China and the US have also clashed over Beijing's sovereignty claims over the entire South China Sea, which is also contested by Taiwan and four other Asean members (Brunei, Malaysia, the Philippines and Vietnam).
Washington has accused Beijing of "being a bully" for deploying troops in the region and its effective control over dozens of islands and atolls where it has built military bases and ports.
Despite small progress made in the Code of Conduct in the South China Sea, negotiated between China and Asean, not much is expected in this regard as measures by the bloc must be agreed upon unanimously, the report said.
Laos and Cambodia, key allies of Beijing, have been known to block measures on previous occasions.
Another focus of the meeting will be the Korean peninsula and the denuclearization process, despite the absence of top representatives from Pyongyang and amid the resumption of North Korean missile tests.
Asean - made up of Myanmar, Brunei, Cambodia, Philippines, Indonesia, Laos, Malaysia, Singapore, Thailand and Vietnam - accounts for a population of 647 million which aims to raise its combined GDP to $4.7 trillion by 2025 and become the world's fourth-largest economic power.
( With inputs from IANS )