Foreign Affairs Secretary Teodoro Locsin Jr. said Wednesday he will call Washington D.C. in case a Filipino vessel is attacked or something that is “beyond incursion” happens in the West Philippine Sea.

Locsin made the statement in light of Beijing’s strong reaction to the diplomatic protest filed by the Philippines last week, calling the country’s conduct of regular maritime patrol “illegal provocations.”

“Until something happens that is beyond incursion that, in fact, is an attack on say, a Philippine vessel -- a naval vessel -- in which case, then I call up Washington D.C.,” the Foreign Affairs Secretary said in an interview over ANC’s Headstart.

Locsin, however, declined to elaborate as to what basis he will call the United States should an attack occurs in the hotly-contested waters of the South China Sea or the West Philippine Sea.

“I will not discuss that because the essence of deterrence theory is uncertainty. I’m a long time student of deterrence theory,” he pointed out.

The DFA Secretary believes that the Republicans under the Trump administration has pivoted to Asia to assert fundamental things, freedom of navigation, independence and sovereignty of states, guarantees against aggression, and to “preserve our country’s freedom.”

"But again, we’re talking here deterrence. The essence of deterrence is uncertainty. You must never know what can happen,” Locsin stressed.

In February last year, US Secretary of State Michael Pompeo assured the Philippines that it will come to its aid if Philippine vessels or forces are attacked in the South China Sea, citing a provision in the 69-year-old Mutual Defense Treaty between Manila and Washington.

"As the South China Sea is part of the Pacific, any armed attack on any Philippine forces, aircraft, or public vessels in the South China Sea will trigger mutual defense obligations under Article 4 of our Mutual Defense Treaty," Pompeo said in a statement during his visit to Manila in February 2019.