U.S. President Barack Obama arrived in Manila on Tuesday for the first of back-to-back Asia-Pacific summits that were supposed to be a chance for the United States to reinforce trade and security ties with the economically dynamic region but which are now clouded by the Islamic State threat half a world away.

Obama's visit to Manila for the Asia-Pacific Economic Cooperation (APEC) gathering on Wednesday and Thursday comes on the heels of the G20 summit in Turkey where discussions about the violence emanating from Syria's 4-1/2-year-old civil war dominated the agenda.

He will then fly to Kuala Lumpur for the ASEAN and East Asia summits.

On his three-day trip to Manila, Obama will also hold bilateral meetings with Philippine President Benigno Aquino and other allies, and meet heads of state of the 12-member Trans-Pacific Partnership group. He will also have a meeting with members of the Pacific Alliance, a Latin-American trade bloc.

Obama's meeting with Aquino is expected to touch on regional tensions over the South China Sea and enhanced military cooperation. The Philippines is one of the United States' oldest allies in the region.