Marcos said Thursday that the Philippines needs to do more than protest Beijing's «illegal actions» in the South China Sea.
Chinese coast guard personnel wielding knives, sticks and an axe surrounded and boarded three Filipino navy boats last week, video showed, foiling what Manila said was a resupply mission to troops manning a grounded warship on Second Thomas Shoal.
It was the latest and most serious incident in a series of escalating confrontations between Chinese and Philippine ships as Beijing steps up efforts to push its claims to nearly all of the strategically located waterway.
«We have filed over a hundred protests, we have already made a similar number of demarches,» Marcos told reporters.
«We have to do more than just that,» he said, without specifying what other steps Manila might take.
The clashes have raised concern the conflict will draw in the United States, which is bound by a 1951 mutual defence pact to come to Manila's aid in case of an «armed attack» on its forces or vessels in the Pacific theatre.
Manila has also raised concerns that Chinese forces might take action against the warship BRP Sierra Madre, an ageing ship that was deliberately grounded on the shoal in 1999 to assert Philippine claims to the area.
A small garrison of Filipino marines stationed aboard the decrepit vessel relies on frequent resupply for survival.
Marcos on Thursday echoed his senior security aides' assessment that the June 17 clash next to the grounded warship did not constitute an armed attack.
«It's not