Marcos told a Philippine Military Academy graduation ceremony that the Southeast Asian country faced "a blatant disregard of internationally accepted principles".
His remarks follow a series of incidents involving Philippine and Chinese vessels near disputed reefs in the South China Sea that have strained diplomatic ties.
Marcos ordered the graduates to "keep our people safe in their homes, our territory secure, our defences against threats strong, and our democracy stable".
"Against intruders who have been disrespecting our territorial integrity, we will vigorously defend what is ours," Marcos said in the speech, which did not specifically mention China.
China Coast Guard vessels have used water cannon against Philippine boats several times in recent months in the contested waters, where there have also been collisions.
Beijing claims most of the South China Sea, brushing off rival claims from other countries, including the Philippines, and an international ruling that its assertion over the waterway has no legal basis.
To press its claims, Beijing deploys coast guard and other boats to patrol the waterway and has turned several reefs into artificial islands that it has militarised.
A Philippine civilian convoy sailed towards Scarborough Shoal to bring fuel and food supplies for Filipino fishermen in the area this week. It later turned back after one of the boats was shadowed by a Chinese navy ship.
China defends its actions by saying that it takes necessary measures against vessels it says are infringing on its territory.
Marcos said the Philippines' conduct would be "always guided by law and our responsibility as a rules-abiding member of the community of nations".
He has said that Manila will not respond in kind to the use of water cannon against its vessels.
Taiwan coast guard ramps up island patrols ahead of inauguration
Kinmen, Taiwan (AFP) May 19, 2024 -
Taipei's coast guard ramped up patrols over the weekend around its outlying islands that have seen increased presence of Chinese vessels, the agency said Sunday, the eve of Lai Ching-te's inauguration as Taiwan's new president.
China claims democratic Taiwan as part of its territory, maintaining a near-daily military presence with frequent appearances of fighter jets, drones and naval ships around the island.
It has also in recent months sent in Chinese coast guard ships around Kinmen, an outlying island administered by Taipei located just five kilometres (three miles) from the Chinese city of Xiamen.
Taipei's Coast Guard Administration said on Sunday they have sent out personnel to "patrol all hours of the day and night" around Taiwan's three major outlying islands: Kinmen, Matsu and Penghu.
"In order to ensure the security of the sea area and border safety during the inauguration ceremony, the Ocean Affairs Council's Coast Guard Administration's Kinmen-Matsu-Penghu Division once again implemented a powerful patrol operation... to closely monitor suspicious targets," it said in a statement.
"The Kinmen-Matsu-Penghu Division said that the national security work will not slacken during the important celebrations," it added.
Kinmen has been the site of ramped up tensions after Lai -- who China has branded a "dangerous separatist" -- was elected in Taiwan's January elections.
A deadly fishing incident in February involving a Chinese speedboat kicked off a row between China and Taiwan, which has yet to be resolved.
It was carrying four people and capsized on February 14 near Kinmen while Taiwan's coast guard was pursuing it, leaving two dead.
Taipei's coast guard had defended its actions, saying the boat was within "prohibited waters" and zigzagging before it capsized, but Beijing has accused Taipei of "hiding the truth" about the incident.
China has since stepped up patrols around Kinmen.
At least five formations of official Chinese ships have briefly sailed through Kinmen's restricted waters this month.
On the eve of Lai's inauguration, Taipei's defence ministry said it had detected seven Chinese aircraft and seven naval vessels around Taiwan in the 24-hour period leading up to 06:00 am (2200 GMT) Sunday.
Across the strait in the Chinese seaside city of Pingtan -- also home to a military base -- AFP reporters saw at least two military transport helicopters fly overhead Sunday morning.
Related Links
Naval Warfare in the 21st Century
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
