NAYPYIDAW, Myanmar - Myanmar welcomed Wednesday its biggest gathering of world leaders since shedding junta rule but concerns over the pace of democratic reforms are expected to surface at the two-day event featuring US President Barack Obama.
The Association of Southeast Asian Nations (ASEAN) and East Asia summits, held in the purpose-built capital of Naypyidaw, are the culmination of a year of diplomatic limelight for Myanmar after long decades shunted to the sidelines under its former military rulers.
Other key issues will include the row between several ASEAN members and China over territory in the South China Sea, and greater economic integration ahead of a Southeast Asian trade union mooted for 2015.
The rise of the self-proclaimed Islamic State and countering the Ebola epidemic are also expected to be discussed by the dignitaries.
At the end of the ASEAN summit on Wednesday, the leaders are expected to release a statement expressing "concerns over recent developments in the South China Sea, which have increased tensions in the area", according to a draft seen by AFP.
Antagonism has soared with violent anti-China clashes breaking out earlier this year in Vietnam over Beijing's activities in contested waters, while the Philippines has also expressed outrage at a series of manoeuvres and naval deployments by the regional superpower.
China says most of the South China Sea - including areas near the coast of rival claimants - is its territory.
The sea row has dogged regional relations for years, with Beijing reluctant to sign a binding, multilateral code of conduct covering disputes in the resource-rich waters.
A spokesman for Philippine President Benigno Aquino said ASEAN leaders on Wednesday again called for "a substantial fleshing out" of the process towards reaching the elusive code.
In the draft statement, the leaders also pledged to take "all necessary measures" to stop ASEAN nationals "travelling to join terrorist groups." Scores, possibly even hundreds, of people from Indonesia, the world's largest Muslim country, and Malaysia have joined Islamic militants in Syria and Iraq.
ASEAN leaders are due to meet with Chinese Premier Li Keqiang on Thursday during the East Asia Summit, which groups the Southeast Asian bloc with the United States, China, India, Japan, South Korea, Australia, Russia and New Zealand.
Support for reforms, tempered with caution
In remarks to open the ASEAN summit, Myanmar's reform-minded President Thein Sein hailed progress on the reduction of trade barriers and tariffs with the goal of a 2015 economic integration fast approaching.
On Wednesday the bloc held meetings with India and Japan before Obama lands in the evening fresh from the Asia-Pacific Economic Cooperation (APEC) summit in Beijing.
Obama is set to meet Thein Sein and opposition leader - and fellow Nobel laureate - Aung San Suu Kyi during his two-night stay in the country, as he throws his political muscle behind reforms and landmark elections slated for late 2015.