Vice-President Kamala Harris would underscore America’s commitment to defending treaty ally the Philippines with a visit due to start on Sunday that includes flying to an island province facing the disputed South China Sea, where Washington has accused China of bullying smaller claimant nations. After attending the Asia-Pacific Economic Cooperation (Apec) summit in Thailand, Harris is expected to travel to Manila and meet President Ferdinand Marcos Jnr for talks on Monday. They are aimed at reinforcing Washington’s oldest treaty alliance in Asia and strengthening economic ties, said a senior US administration official, who was not identified according to practice, in an online briefing ahead of the visit. On Tuesday Harris will fly to Palawan province, which lies along the South China Sea, to meet local fishermen, villagers, officials and the coastguard. Once there, she will be the highest-ranking US leader to visit the frontier island at the forefront of the long-seething territorial disputes involving China, the Philippines, Vietnam, Malaysia, Brunei and Taiwan. The Philippine coastguard is expected to welcome Harris on board one of its largest patrol ships, the BRP Teresa Magbanua, in Palawan, where she is expected to deliver a speech to coastguard, police, military and government officials, according to coastguard spokesperson Commodore Armand Balilo. Harris will underscore the importance of international law, unimpeded commerce and freedom of navigation in the South China Sea, the US official said. In response to a question, the official added that China can view the visit the way it wants but Washington’s message is that the US, as a member of the Indo-Pacific, is engaged and committed to the security of its allies in the region. Philippine Ambassador to Washington Jose Manuel Romualdez said Harris’s trip to Palawan shows the level of America’s support to an ally and concern over China’s actions in the disputed sea. “That’s as obvious as you can get, that the message they’re trying to impart to the Chinese is that ‘we support our allies like the Philippines on these disputed islands,’” Romualdez told Associated Press. “This visit is a significant step in showing how serious the United States views this situation now.” Washington and Beijing have long been on a collision course in the contested waters. While the US lays no claims to the strategic waterway, where an estimated US$5 trillion in global trade transits each year, it has said that freedom of navigation and overflight in the South China Sea is in America’s national interest. China opposes US navy and air rorce patrols in the busy waterway, which Beijing claims virtually in its entirety. It has warned Washington not to meddle in what it says is a purely Asian territorial conflict – which has become a delicate frontline in the US-China rivalry in the region and has long been feared as a potential Asian flashpoint. In July, US Secretary of State Antony Blinken called on China to comply with a 2016 arbitration ruling that invalidated Beijing’s vast territorial claims in the South China Sea and warned that Washington is obliged to defend treaty ally Philippines if its forces, vessels or aircraft come under attack in the disputed waters. China has rejected the 2016 decision by an arbitration tribunal set up in The Hague under the United Nations Convention on the Law of the Sea after the Philippine government complained in 2013 about China’s increasingly aggressive actions in the disputed waters. Beijing did not participate in the arbitration, rejected its ruling as a sham and continues to defy it. Harris’ visit is the latest sign of the growing rapport between Washington and Manila under Marcos Jnr, who took office in June after a landslide electoral victory. Xi-Biden talks in Bali will not ease South China Sea tensions, analysts say America’s relations with the Philippines entered a difficult period under Marcos’ predecessor, Rodrigo Duterte, who threatened to sever ties with Washington and expel visiting American forces, and once attempted to do away with a major defence pact with the US while nurturing cosy ties with China and Russia. When President Joe Biden met Marcos Jnr for the first time in September in New York on the sidelines of the UN General Assembly, he stressed the depth by which the US regards its relations with the Philippines despite some headwinds. “We’ve had some rocky times, but the fact is it’s a critical, critical relationship, from our perspective. I hope you feel the same way,” Biden said. “We continue to look to the United States for that continuing partnership and the maintenance of peace in our region,” Marcos Jnr told Biden. “We are your partners. We are your allies. We are your friends.” South China Sea: Philippines complains of Chinese ‘harassment’ at sea The rapprochement came at a crucial time when the US needed to build a deterrent presence amid growing security threats in the region, Romualdez said. Philippine military chief of staff Lieutenant General Bartolome Bacarro said last week that the US wanted to construct military facilities in five more areas in the northern Philippines under a 2014 defence cooperation pact, which allows American forces to build warehouses and temporary living quarters within Philippine military camps. The Philippines Constitution prohibits foreign military bases but at least two defence pacts allow temporary visits by American forces with their aircraft and Navy ships for joint military exercises, combat training and bracing to respond to natural disasters. The northern Philippines is strategically located across a strait from Taiwan and could serve as a crucial outpost in case tensions worsen between mainland China and the self-governed island. While aiming to deepen ties, the Biden administration has to contend with concerns by human rights groups over Marcos Jnr. The Philippine leader has steadfastly defended the legacy of his father, a dictator who was ousted in a 1986 pro-democracy uprising amid human rights atrocities and plunder. Harris also plans to meet Vice-President Sara Duterte, daughter of Marcos’ predecessor, who oversaw a deadly anti-drugs crackdown that left thousands of mostly poor suspects dead and sparked an International Criminal Court investigation as a possible crime against humanity. Duterte has defended her father’s presidency. Given the Biden administration’s high-profile advocacy for democracy and human rights, its officials have said human rights were at the top of the agenda in each of their engagements with Marcos Jnr and his officials. After her meeting on Monday with Marcos Jnr, Harris plans to meet civil society activists to demonstrate US commitment and continued support for human rights and democratic resilience, the US official said.