MANILA – The United States knew that a war “about something so small” like the Scarborough Shoal in the disputed South China Sea was “not worth it”, President Rodrigo Duterte said Sunday, as he again conceded that the Philippines cannot rely on its long-standing Pacific ally to defend Manila’s interests in the vital sea lane.

Scarborough, called by Filipinos as Panatag Shoal and by the Chinese as Huangyan Island, was the site of a 2012 standoff between the Philippines and China. The standoff erupted when Manila sent its biggest warship to chase off Chinese poachers.

Duterte recalled how the US brokered a deal for the Philippines and China to withdraw their respective ships from the resource-rich fishing ground, “but China refused to follow” even though the Philippines pulled out its Navy flagship, BRP Gregorio del Pilar.

The President said the US, the Philippines’ only treaty ally, knew that a war in the vital maritime route would be destructive, which is why it brokered such a deal.

"[Albert] del Rosario was Aquino’s Foreign Affairs Secretary. He was the only one who negotiated. But America was scared. They knew that a war about something so small is not worth it,” Duterte said in a speech during the campaign sortie of PDP-Laban in Agusan del Norte.

Duterte added, if China “hit us and America decides to help, it could trigger a world war. America knows it. Everybody does.”

The Aquino government said Beijing did not honor the deal, effectively placing Scarborough Shoal, located only 124 nautical miles off Zambales and is within the Philippines’ 200-nautical mile exclusive economic zone, under its control.

The Scarborough standoff prompted the Aquino government to drag Beijing to an international tribunal to invalidate the Asian power’s expansive claims to the sea.

The United Nations-backed arbitral tribunal ruled in favor of the Philippines, but Beijing has refused to honor its decision.

China has since built artificial islands in some of the features in the Spratlys archipelago, located off Palawan.

Duterte hit Beijing for its island-building activities, as he also blamed the US for failing to stop its regional rival from fortifying its claims to the sea.

“Over the years while the case was heard in the arbitral court, they started building. So why did they not go there when China situated their ship there?” he said.

“America did not do anything. Now it’s almost complete. It looks like a real camp. They have guns. They want me to visit it. It’s fine, it can be done just to show off. But we would all be destroyed. And my soldiers and my policemen will be massacred.”

Duterte said he doubts whether the US will back up Filipino forces should Manila decide to assert its claim on the sea by force.

“Will America join us? They can’t even resolve their problem with Iraq and Iran in the Middle East. They’ve been at war for a long time. But who won it? Nobody,” he said.

The Philippines and the US signed a 1951 defense treaty that requires one to defend the other in case of an attack in its territory.

But questions have been raised as to the Americans' sincerity in upholding the commitment as the Philippines dealt with China in the South China Sea dispute.

Defense Secretary Delfin Lorenzana previously said it was the US interpretation that the treaty covers only "metropolitan" Philippines, noting that this does not include Philippine-occupied areas in the West Philippine Sea, the country's exclusive economic zone in the disputed South China Sea.

Filipino troops are currently occupying 9 areas in the South China Sea, and the largest, Pag-asa Island, serves as the seat of government of Kalayaan town in Palawan.

Lorenzana said the Americans were "ambivalent" when it comes to the issue on whether the Philippine-occupied areas in the South China Sea are included in "metropolitan" Philippines.

The Philippines has long been at odds with China over several features in the West Philippine Sea where Beijing claims ownership.

Ties between Beijing and Manila, however, have substantially warmed under the leadership of Duterte who refused to assert Manila's claims in the disputed waters in exchange for investment opportunities with Asia's largest economy.

Duterte’s rapprochement with Beijing, however, has recently come under intense criticism following China’s aggressive actions in the disputed waterway.