Asia-Pacific leaders on Sunday wrap up a week of diplomacy on trade and security issues that has been jolted by revulsion over the recent jihadist attacks.
Heads of government from 18 countries including the United States, China, India, Japan and Southeast Asia hold an annual summit hosted this year by Malaysia.
At the summit President Barack Obama and other leaders on Saturday expressed the rising international alarm over the deadly attacks in Paris, Mali and Lebanon, calling for global co-operation to fight extremism.
"The perpetrators of these cowardly and barbaric acts do not represent any race, religion or creed," Prime Minister Najib Razak of Muslim-majority Malaysia told the summit.
"They are terrorists." The Kuala Lumpur diplomatic-political meetings follow a trade-related forum in Manila earlier in the week that included many of the same leaders and similar expressions of concern over terrorism.
Obama is on something of a victory lap for his newly signed 12-country Trans Pacific Partnership trade pact, which Washington is pushing signatories in the region to ratify so it can eventually be implemented.
China's push to expand tiny atolls in the South China Sea into full islands capable of supporting a sustained military presence also has hung over the meetings.
Obama met Saturday with his ASEAN counterparts, and a joint statement emerged that stressed the need to maintain freedom of navigation and over-flight in the South China Sea.
Washington has warned that traffic through the South China Sea, a key conduit for world trade, could be threatened by China's moves.
It recently sent US naval vessels to the region to stress the right to free passage, a move that angered Beijing.
Earlier in Manila, Obama called on China to cease the island-building, while announcing hundreds of millions of dollars of new aid to regional allies worried by China's territorial assertiveness.
China insists on sovereignty over virtually all the strategic and resource-endowed South China Sea, which also is claimed in part by a handful of other countries.
Southeast Asian foreign ministers who met Friday in Kuala Lumpur issued a joint statement saying they were "seriously concerned" over the land reclamation.
In Kuala Lumpur, Southeast Asia leaders will declare the establishment on Sunday of an "ASEAN Economic Community" (AEC), inspired by Europe.
The move takes ASEAN a step closer to an envisioned single Southeast Asian market with free flow of goods, capital and skilled labour across borders.
But the AEC's realisation remains a distant goal - if it is ever fully achieved - due to significant non-tariff and other barriers and large development gaps across the diverse region, and the declaration is largely symbolic.