The Chinese and Philippine Coast Guards exchanged radio challenges as a Chinese monster ship continued to lurk near the Southeast Asian country's coastline.

Video shows crew of the Philippine ship BRP Gabriela Silang issuing a warning to the massive China Coast Guard (CCG) vessel 5901 seen sailing 70 nautical miles off the Philippine province of Zambales on January 15.

The CCG ship responded with its own radio challenge, telling the Filipino crew to 'comply with international regulations for preventing collisions at sea'.

Philippine spokesman Commodore Jay Tarriela said the CCG 5901 has been 'loitering' in the area for around 11 days.

He said: 'This particular deployment is questionable because this is the first time that the China Coast Guard deployed that close to our exclusive economic zone. This has never happened before. The Chinese Coast Guard does not have the legal authority to patrol within our own exclusive economic zone.'

Jonathan Malaya, assistant director of the National Security Council, China was 'pushing the Philippines to the wall' with the presence of the 'monster ship'.

He said: 'You're pushing us to the wall. We do not and will not dignify these scare tactics by backing down. We do not waver or cower in the face of intimidation. On the contrary, it strengthens our resolve because we know we are in the right.'

The National Maritime Council said the Philippine government has filed a diplomatic protest over the 'illegal presence' and 'provocative actions' of the China Coast Guard.

The massive CCG 5901, the world's largest coast guard vessel at 541 feet and 12,000 tons, started lurking off the seaside province on January 4 afternoon. Another CCG ship had headed to the area to replace it on January 8, before it circled back to the area, officials said.

Authorities believe it was deployed to intimidate Filipino fishermen from entering the Scarborough Shoal, a disputed fishing ground and resource-rich area in the South China Sea.

Expansionist China currently lays claim over almost the entire South China Sea, one of the world's busiest sea lanes. But a United Nations-backed tribunal in 2016 deemed its claims groundless.

The Communist rogue state - accused of genocide for its crimes against the Uyghur population - has been steadily increasing its influence in recent years through investment in developing countries.