MANILA (Reuters) -Philippine President Ferdinand Marcos Jr said on Saturday the country will "vigorously defend what is ours", in a thinly veiled reference to mounting tensions with China over maritime disputes.

The conduct against intruders disrespecting Philippine territorial integrity will be guided by law and the responsibility as a rules-abiding member of the international community, Marcos said in a speech to graduating military cadets.

"Against intruders who have been disrespecting our territorial integrity, we will vigorously defend what is ours," Marcos said.

He did not identify the intruders, but Manila and Beijing have been in escalating standoffs in the South China Sea, including China's use of water cannon that resulted in injuries and property damage, a military-grade laser directed at Philippine vessels and what the Philippines calls "dangerous manoeuvres" in the disputed waterway.

China claims almost all the South China Sea, a conduit for $3 trillion in annual ship-borne trade, including parts claimed by the Philippines, Brunei, Malaysia, Taiwan and Vietnam. A 2016 ruling by the Permanent Court of Arbitration found that China's sweeping claims have no legal basis.

(Reporting by Neil Jerome Morales; Editing by William Mallard)