Carrying placards declaring "Dump Trump" and "Down with US Imperialism", the left-wing protesters were blocked by police in riot gear with shields and batons, and then showered with jets of water from a fire engine.
"Trump is the CEO of the imperialist government of the US," said 18-year-old student Alexis Danday after the protesters were scattered. "We know he is here to push for unfair treaties between the Philippines and the US"
Trump was expected to arrive in the Philippines at around 5 PM (0900 GMT) for meetings with leaders of the Association of Southeast Asian Nations (ASEAN) and other East Asian nations, fresh off an Asia-Pacific summit and bilateral visit in Vietnam.
In Hanoi earlier on Sunday, Trump said he was prepared to mediate between claimants to the South China Sea, where four ASEAN countries and Taiwan contest China's sweeping claims to the busy waterway.
"If I can help mediate or arbitrate, please let me know," Trump said at a meeting with Vietnam's president, Tran Dai Quang. "I'm a very good mediator and arbitrator."
In August, foreign ministers of Southeast Asia and China adopted a negotiating framework for a code of conduct in the South China Sea, a move they hailed as progress but one seen by critics as a tactic to buy China time to consolidate its power.
The framework seeks to advance a 2002 Declaration of Conduct (DOC) of Parties in the South China Sea, which has mostly been ignored by claimant states, particularly China, which has built seven man-made islands in disputed waters, three of them equipped with runways, surface-to-air missiles and radars.
The framework will be endorsed by China and the 10 nations of ASEAN in Manila on Monday, a diplomat from one of the regional bloc's countries said.
Last Stop On Marathon Tour
The Philippines will be Trump's last stop on a marathon tour that has taken him to Japan, South Korea, China as well as Vietnam. Despite Trump's "America First" policy, the visit should provide some reassurance that Washington remains committed to a region that Beijing sees as its strategic domain.
The increasing use of the phrase "Indo-Pacific" by Trump and his team during their Asian tour this week, instead of the more common "Asia-Pacific" term has been seen by analysts as an effort to depict the region as more than China-dominated.
Pacific Rim nation leaders agreed in Vietnam on Saturday to address "unfair trade practices" and "market distorting subsidies", a statement that bore the imprint of Trump's efforts to reshape the global trade landscape.
The summit of Asia-Pacific Economic Cooperation (APEC) countries in Vietnam put on show the contrasting vision of the "America First" policy with the traditional consensus favouring multinational deals that China now seeks to champion.
Trump will meet Philippine President Rodrigo Duterte in Manila, where he will try to shore up relations strained by the mercurial Duterte's notorious anti-US sentiment and his enthusiasm for better ties with Russia and China.
Others who will be in Manila for the summit meetings include Chinese Premier Li Keqiang, Russian Prime Minister Dmitry Medvedev and leaders from Japan, Canada, South Korea, India, Australia, New Zealand as well as the member states of ASEAN.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)