The Philippines "cannot yield" in territorial disputes, President Ferdinand Marcos said Monday, after a series of escalating confrontations with Beijing in the South China Sea.

Manila is locked in a longstanding territorial row with Beijing over parts of the strategic waterway through which trillions of dollars worth of trade passes annually.

Without naming China, Marcos said the Philippines would continue to "find ways to de-escalate tensions in contested areas... without compromising our position and our principles".

"The Philippines cannot yield. The Philippines cannot waver," Marcos said in his annual State of the Nation address to Congress.

His remarks came after the Philippines and China agreed to a "provisional arrangement" for resupply missions to Filipino troops stationed at Second Thomas Shoal, which has been the focus of violent clashes in recent months.

Beijing claims almost the entire South China Sea and asserts its stance by deploying coast guard and other vessels to patrol the disputed waters and reefs. 

Philippine relations with China have been turbulent since Marcos took office in 2022 vowing to defend his country's claims to the South China Sea.

A series of clashes between Philippine and Chinese vessels at flashpoint reefs have fuelled fears of a conflict that could drag in the United States owing to its mutual defence treaty with Manila.

The pact requires both parties to come to the other's defence in case of an "armed attack" against vessels, aircraft, military and coast guard anywhere in the Pacific theatre, which Washington says includes the South China Sea.

The Philippines has also deepened defence cooperation with other countries, including Australia, France and Japan, in the face of China's growing assertiveness in the waterway.

Manila signed a key defence pact with Tokyo this month that will allow the deployment of troops on each other's territory. 

"We are continuing to strengthen our defensive posture both through developing self-reliance and through partnerships with like-minded states," said Marcos, who received a standing ovation when he declared "the West Philippine Sea... is ours".

Manila calls the South China Sea waters to the country's immediate west the West Philippine Sea.

Beijing has brushed aside competing claims to the South China Sea from several Southeast Asian nations, including the Philippines, and an international ruling that its expansive claims have no legal basis.

VP Duterte absent

Marcos highlighted the government's efforts to boost agriculture, prepare for natural disasters, build highways and bridges, and improve the education system.

There were loud cheers when he declared an immediate ban on online gambling operations in the country, which are mostly run by Chinese nationals and have been linked to scams, kidnapping, prostitution, torture and murder.

They flourished under former president Rodrigo Duterte, but there have been growing calls for them to be outlawed after allegations that a local mayor had links to one that was also running a massive scam centre north of Manila.

"We hear the loud complaints of our countrymen," Marcos said to a standing ovation. "We must stop this troublemaking in our society and the abuse of our country."

Lawmakers, foreign diplomats and judges were among the audience, but noticeably absent was Vice President Sara Duterte, who previously announced she would not attend.

Domestic politics have been rocked by the public rupture of an alliance between the Marcos and Duterte families as they attempt to shore up their rival support bases and secure key positions ahead of the 2025 mid-term elections. 

Duterte, the daughter of the former president, quit her cabinet post of education secretary in June.

Police with riot shields stood by as about two thousand protesters marched along a major avenue in Manila in the hours leading up to Marcos's speech to demand higher wages and greater efforts to combat corruption.