RIOT police blasted protesters with water cannons to keep them away from the US embassy in Manilla ahead of Donald Trump’s arrival in the Philippines on the final leg of his Asia tour.

About 3500 people took to the streets of the capital carrying placards bearing messages such as “Dump Trump” and “Down with US Imperialism”. The demonstrators clashed with police who held them back with shields and batons.

There were no immediate reports of injuries in the brief scuffle and the protesters left after burning a mock US flag.

US president Trump attended a gala dinner in Manila last night held to mark the 50th anniversary of the Association of Southeast Asian Nations (ASEAN). Hosted by the controversial president of the Philippines, Rodrigo Duterte, its guest list included nearly 20 world leaders, such as Russian prime minister Dmitry Medvedev, Chinese premier Li Keqiang and Japanese prime minister Shinzo Abe.

Trump will attend a series of summits organised by the ASEAN, which start today.

Earlier, Trump offered to mediate in the South China Sea disputes, while his Chinese counterpart, Xi Jinping, played down concerns over Beijing’s military build-up and the prospects of war in the contested waters.

The pair spoke separately about what will be a key issue at the summits, along with the North Korean nuclear threat and terrorism. The US and China are both calling for a peaceful resolution but take contrasting positions in most other aspects of the conflict.

Unlike China, the US is not a claimant to the potentially oil-rich and busy waters, but it has declared it has a national interest in ensuring freedom of navigation and overflight and the peaceful resolution of the disputes.

Several nations back an active American military presence in the region to serve as a counterweight to China’s increasingly assertive actions, including the construction of seven man-made islands equipped with military installations.

“I’m a very good mediator and arbitrator,” Trump claimed at a news conference with Vietnamese president Tran Dai Quang in Vietnam’s capital, Hanoi, before flying to Manila.

His offer faces major obstacles, as China has steadfastly opposed what it calls US meddling in the disputes and is unhappy about the US navy’s incursions into what Beijing considers its territorial waters in the South China Sea.

The Philippines, the head of ASEAN’s rotational chairmanship, said member states of the 10-nation bloc have to consult each other but thanked Trump for the offer.

Philippine foreign secretary Alan Peter Cayetano said: “He is the master of the art of the deal but, of course, the claimant countries have to answer as a group or individually ... mediation involves all the claimants and non-claimants,”

Duterte discussed the issue with Xi during a meeting in Danang, Vietnam, where they attended the annual Asia-Pacific Economic Co-operation forum last week.

The Philippine president said Xi assured him of China’s peaceful intentions in the strategic waterway, where Beijing, the Philippines, Vietnam and three other governments have overlapping claims.

Duterte said: “He acknowledged that war cannot be promoted by anybody – it would only mean destruction for all of us. He knows that if he goes to war, everything will blow up.”

However, he added that Xi would not back down on Beijing’s territorial claim.