US President Barack Obama and other Asia-Pacific leaders arrived in the Philippines Tuesday for a summit meant to foster trade unity but with terrorism and territorial rows likely to dominate.
The two-day Asia-Pacific Economic Cooperation (APEC) summit will begin Wednesday under the global shadow cast by last week's jihadist rampage in Paris that killed at least 129 people.
While the 21-member APEC group's mission is to promote trade, the leaders will undoubtedly discuss the events in the French capital and efforts to counter the Islamic State (IS) group, which has claimed responsibility for the carnage.
Obama, Chinese President Xi Jinping and a host of other leaders arrived in Manila from Turkey, where they attended a summit of the Group of 20 top economies that also focused heavily on IS and how to destroy the jihadist network.
Islamic State leaders "will have no safe haven anywhere", Obama said at the G20 summit, vowing a ruthless pursuit of the group.
Philippine authorities, which had already deployed more than 20,000 police and soldiers for the summit, said security had been ratcheted up even higher because of the Paris attacks.
Parts of the chaotic capital of 12 million people have been brought to a standstill this week to ensure security for the leaders, with key roads closed, barricades erected and a deliberately visible presence of security forces.
- Territorial tensions -
Another sensitive issue this week will be China's recent efforts to assert control over the South China Sea, which is home to some of the world's most important shipping lanes.
The other claimants are APEC members Vietnam, the Philippines, Malaysia, Brunei and Taiwan.
The Philippines, one of China's most vocal critics in the row, has promised to be a "perfect host" to Xi.
But while keeping the dispute off the official APEC agenda, Philippine President Benigno Aquino appears to be using the summit as an opportunity to firm up alliances aimed at countering China.
Obama's first public function in Manila will be to tour the Philippine Navy's flagship vessel, the US-made Gregorio del Pilar, which is providing APEC security in Manila Bay.
Obama's aides had previously said Obama would tour the ship to showcase American commitment to providing maritime security in the region.
The US president is also due to give a speech to a pre-summit forum on Wednesday morning, which his aides have said would address maritime security, a term commonly used in reference to sea rows.
China's building of artificial islands in parts of the South China Sea close to the Philippines had already prompted the US military to deploy a missile destroyer and B-52 bombers to the area.
The Philippines, which has one of the weakest militaries in Asia, has in recent years sought to draw longtime ally the United States into the dispute as a protector against China.
Aquino and Vietnamese President Truong Tan Sang are also set to oversee on Tuesday afternoon the signing of a bilateral strategic partnership that will deepen defence ties.
The Philippines and Vietnam have been brought closer in recent years by their shared concerns over China, with the imminent strategic partnership the most significant development.
Any focus on the South China Sea in the Philippines will irk China, which has insisted the APEC forum should stick solely to trade issues.
It has also repeatedly said the United States has no role to play in the dispute.