MANILA (UPDATE) — The Philippines on Wednesday denied promising China that it would remove the BRP Sierra Madre from Ayungin Shoal, which Manila uses to assert its stake over the Spratly Islands in the West Philippine Sea.

A spokesperson for China's foreign ministry on Tuesday said the Philippines supposedly "made clear promises to tow away the warship illegally 'stranded' on the reef."

Beijing renewed its call for the aging ship's removal days after Manila accused the China Coast Guard of firing water cannon against Philippine boats on a resupply mission to marines stationed on the BRP Sierra Madre.

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"Walang ganoon. Walang meeting, walang kasulatan na nilagdaan ng dalawang bansa na mayroon tayong ganoong usapan," National Security Council (NSC) assistant director general Jonathan Malaya said.

"I can categorically say to the public na walang administrasyon na nangakong tatanggalin 'yan... kung may ganoong kasunduan, ilabas niyo, they are the ones making this claim, therefore it is their responsibility to back up their claim," he said in a public briefing.

(There is no such promise. There is no meeting or agreement signed by the two countries on this. I can categorically say to the public that no administration promised to remove that. If there is such an agreement, they should make that public. )

• On Board the BRP Sierra Madre

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"If China firmly believes na mayroong ganoong kasunduan o pangako, sabihin nila sino ang nangako. Kasi baka naman ang nangako sa kanila ay hindi opisyal ng pamahalaan," he added.

(If China firmly believes that such an agreement or promise exists, they should name who made that promise. The person who may could have made the promise may not be a government official.)

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The BRP Sierra Madre was deliberately grounded in 1999 in an effort to check the advance of China in the hotly contested waters.

The handful of Philippine marines deployed on the crumbling vessel depend upon resupply missions to survive their remote posting.

The Philippine military and coast guard accused the China Coast Guard of breaking international law by blocking and firing water cannon at the resupply mission, preventing one of the charter boats from reaching the shoal.

China has defended its recent actions as "professional" and accused the Philippines of "illegal delivery of construction materials" to the grounded ship.

"Twenty-four years have passed, the Philippine side has not only failed to tow away the warship, but also attempted to repair and reinforce it on a large scale to achieve permanent occupation of the Ren'ai Reef," a foreign ministry spokesperson said, using the Chinese term for the Ayungin Shoal.

• China demands Philippines remove grounded ship from disputed waters

The Philippine foreign affairs department said the "permanent station" on Second Thomas Shoal was in response to China's "illegal occupation" of nearby Panganiban Reef in 1995.

"The deployment of a Philippine military station in its own areas of jurisdiction is an inherent right of the Philippines and does not violate any laws," the agency said.

• Philippines rejects China claim, says Ayungin garrison 'legitimate'

Ayungin Shoal is about 200 kilometers from the Philippine island of Palawan and more than 1,000 kilometers from China's nearest major landmass, Hainan island.

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China's blockade of ship deliberate, premeditated: Experts

Experts, for their part, said China’s actions in the West Philippine Sea last August 5 was a clear escalation of the situation.

Analyst Raymond Powell said 42 Chinese militia vessels have been monitored around Mischief Reef, which is only about 20 nautical miles away from the Ayungin Shoal.

For Powell, China’s actions were deliberate and in fact, the presence of numerous vessels is an indication that it made preparations to stop the latest resupply mission, describing it as a "blockade."

Maritime expert and UP Professor Jay Batongbacal meanwhile against the loose usage of the term because it is internationally recognized as an act of war.

“Blockades," he said, are particularly regulated by the 1856 Paris Declaration Respecting Maritime Law and by Articles 1–22 of the 1909 London Declaration Concerning the Laws of Naval War.

Batongbacal said China has been using gray zone tactics which involves coercion and the employment of unconventional force such as the use of water cannons instead of arms, as well as dangerous maneuverings instead of directly ramming Philippine vessels, to avoid being branded as an act of war.

However, the effect is the same.

Various proposals are being explored to deescalate the situation including ASEAN negotiations for a Code of Conduct in the South China Sea, particularly the demilitarization of the region.

But both Batongbacal and Powell are convinced that such negotiations may not prosper, especially since China is not showing any indication of withdrawing its position that it has historical rights over majority of the South China Sea.

Batongbacal, however, agreed of proposals to elevate the situation at the UN General Assembly to help further mobilize international support for the Philippines.

But in a statement, China reiterated that the Philippines entered in a consensus to handle maritime issues through direct negotiations and warner sternly against so-called “hype tactics” and the involvement of “third-party forces.”

Malaya responded by saying that the latest incident proved concerted efforts between the China Coast Guard, Chinese Navy and Chinese militia vessels to stop the Philippine rotation and resupply mission within the country’s own Exclusive Economic Zone, calling it a “blockade” as well.

— with a report from Zen Hernandez, ABS-CBN News; Agence France-Presse