Philippine President Ferdinand Marcos Jr. says his country won't make any concessions on its territorial claims in the South China Sea. But he expressed willingness to ease tensions with China through dialogue, at a time when Beijing is flexing its muscles in the disputed waters.

Marcos made the remarks Monday in his State of the Nation Address.

He said: "We continuously try to find ways to de-escalate tensions in contested areas with our counterparts without compromising our positions and our principles. The Philippines cannot yield. The Philippines cannot waver."

He also said "proper diplomatic channels and mechanisms under the rules-based international order" is the only acceptable way of settling disputes.

He added his country will continue to strengthen its defensive posture "both through developing self-reliance and through partnerships with like-minded nations."

In recent months, clashes between Beijing and Manila in the South China Sea have ramped up. Chinese coast guard vessels have repeatedly fired water cannons at Philippine ships and blocked supply missions to a military outpost in the contested Second Thomas Shoal. Some cases resulted in injuries on the Philippine side.

On Sunday, the Philippines said it has reached a provisional agreement with China over resupply missions to the shoal. Details of the deal weren't immediately disclosed.

China has accused the Philippines of bringing construction materials to the military outpost, which Manila uses to assert its sovereign rights in the area.