Asia-Pacific leaders meeting in Malaysia on Saturday condemned the string of Islamic extremist attacks from Paris to Mali, urging an international effort to fight the scourge.
Prime Minister Najib Razak of Muslim-majority Malaysia opened a fresh round of summitry in Kuala Lumpur by railing against the ideological mantle claimed by Islamic militants.
"The perpetrators of these cowardly and barbaric acts do not represent any race, religion or creed," he told fellow Southeast Asian leaders. "They are terrorists."
US President Barack Obama condemned the violence typified by the "appalling" jihadist hostage siege in Mali that left at least 27 dead, including an American citizen.
"This barbarity only stiffens our resolve to meet this challenge," he said in Kuala Lumpur, referring to global jihadism.
Obama and his counterparts are meeting in the Malaysian capital for round two in a week of back-to-back regional meetings.
The top-level diplomacy kicked off in Manila with a summit of the 21-member Asia-Pacific Economic Cooperation (APEC) bloc.
APEC ended with an urgent call for cooperation against extremism following the attacks in Paris by Islamic State group adherents that killed 130.
Most of the same leaders have now shifted to Malaysia for the meeting of the 10-member Association of Southeast Asian Nations (ASEAN), which expands Sunday into a broader forum including the United States, China, Russia and others.
Unease over China's push to expand tiny atolls into fully-fledged islands to press its disputed South China Sea territorial claims also looms over the talks.
In Manila, Obama called on China to cease the island-building -- which has stoked concerns of a violent confrontation -- and announced hundreds of millions of dollars of new aid to regional allies.
China insists it has 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 held a stage-setting meeting on Friday in Kuala Lumpur issued a joint statement saying they were "seriously concerned" over the situation.
They reiterated a call -- which is typically aimed at China -- for rival claimants to avoid provocative actions that could threaten the tense, if peaceful, status quo.
In Kuala Lumpur, Southeast Asia leaders will declare the establishment on Sunday of an "ASEAN Economic Community" (AEC), inspired by Europe.
That takes a step closer towards an envisioned single Southeast Asian market with free flow of goods, capital and skilled labour across borders.
But the AEC as a reality remains far-off due to significant non-tariff barriers, vested interests, and large development gaps between member states, and the declaration is largely symbolic.
ASEAN leaders will also sign a new convention against human trafficking.
The region was shaken by a refugee crisis earlier this year that included the discovery of brutal human-trafficking camps in Thailand and Malaysia.
Further discussion of the new 12-country Trans Pacific Partnership trade pact spearheaded by the United States -- which hopes to push signatory countries to ratify the deal at home -- also is expected.