The 21st Association of Southeast Asian Nations (ASEAN) Summit opened in the Cambodian capital of Phnom Penh on Sunday with ASEAN Community building high on the agenda.

Cambodian Prime Minister Hun Sen, the rotating chair of ASEAN this year, presided over the summit under the theme "One Community, One Destiny".

In his opening address, Hun Sen said the summit took place at a time when ASEAN has made great achievement in cooperation over the past 45 years, particularly the recent accomplishment in ASEAN Community building.

To take stock of implementation during the past years and to find appropriate solutions to further accelerate the pace of ASEAN Community building, strengthen ASEAN's external relations and enhance ASEAN centrality and international status, ASEAN members should "adopt a more comprehensive and cooperative approach, particularly through ASEAN cooperation," he said.

According to Hun Sen, realizing ASEAN Community by 2015 should remain top priority of ASEAN.

"We should continue to exert our efforts in finalizing a complete legal framework in line with the ASEAN Charter in order to improve the operational efficiency of ASEAN institutions and processes," he noted.

The prime minister said that maintaining regional peace and security is indispensable for ASEAN's prosperity and inclusive growth in the entire ASEAN region.

The 10-member regional bloc should "continue to work together to maintain ASEAN centrality in the regional architecture and further strengthen cooperation with its partners at all levels, especially through the ASEAN plus One and ASEAN plus Three frameworks based on concrete strategies and action plans on economic cooperation including trade."

Hun Sen highlighted enhancing and expanding cooperation among ASEAN ministers in addressing regional and global challenges, such as financial and economic crisis, climate change, the depletion of natural resources, and pandemics.

ASEAN Institute for Peace and Reconciliation, which was put forward at last year's ASEAN summit in Bali, Indonesia, was officially launched at the opening ceremony.

Founded in 1967, ASEAN groups Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam.

The ASEAN summit precedes an ASEAN-plus-three summit and the East Asia Summit which brings together the leaders of ASEAN and its dialogue partners -- the United States, China, Japan, South Korea, Russia, India, Australia and New Zealand.