The Philippine National Security Council appealed for additional defence funding on Thursday, following reports of about 18 Chinese maritime vessels intruding Philippine territorial waters.

Deputy Director-General Vicente Agdamag made the appeal, saying that it is crucial to stream more resources into the country's defence program as China works double time to establish control over the West Philippine Sea.

"Right now, there are 18 maritime surveillance ships operating in our area," Mr Agdamag said during the Philippine Air Force's Air Power Symposium 2013 held in Manila.

The official did not go into details as to the type of ships deployed and locations they are found. But he cited several incidents that underscored China's aggressive moves in the region.

One of these is China's reported imposition of an "exclusion zone" in the Scarborough Shoal, which is by all means a part of the exclusive economic zone of the Philippines.

Known as Bajo de Masinloc, the shoal is just 124 nautical miles from the country's Zambales province.

The Chinese intrusion of the Scarborough Shoal started in April 2012 when Beijing surveillance ships barred the Philippine Navy from apprehending Chinese fishermen who were found poaching endangered marine resources.

More Resources Needed

During the symposium, Mr Agdamag underscored the need for additional defence budget to give the military the capability to impose a "risk that a hostile force would find unacceptable."

He suggested that the defence investment be raised from 0.5 per cent to one per cent of the country's gross domestic product (GDP). He said that at present, defence spending is just equivalent to 1.1 per cent of the total P2.006 trillion budget of the national government.

Reports indicate that China has been actively erecting structures in disputed areas to assert territorial claims. This has caused serious concerns not just for the Philippines but also for other countries laying claims to the region.

Chinese Invasion

Over the years, China has been actively building structures in areas that are well within Philippine territory.

It has constructed a military post in the Mischief Reef (Panganiban Reef), an area that is just 70 nautical miles from Palawan, Philippines. Since 1995, the reef has been occupied by China.

What they did was build stilted structures at the area supposedly just to shelter fishermen, but these were eventually transformed into a military barracks, complete with powerful radars.

China also intruded into Subi Reef, an islet that is just 12 nautical miles southwest of Pag-Asa Island. They erected a strong radar station in the reef which is a part of the Philippines' Kalayaan group of islands. Seven years ago, they began building a four-level structure in the area, including a lighthouse.

Very recently, China also deployed ships in the Ayungin Shoal, another territory within the Philippines' exclusive economic zone. Ayungin is located 105.77 nautical miles from Palawan.