The US and the Philippines kick started another edition of the joint military exercises -- which China sees with skepticism given the regional maritime tensions -- with Manila quipping Beijing is "not part of the idea."
As many as 8,000 US and Philippine troops will take part in military drills over the next two weeks. Philippine defense officials said the activities include testing command-and-control, communications, logistics and mobility protocols.
The troops will also simulate retaking an oil-and-gas platform and practice an amphibious landing on a Philippine beach, Reuters reported.
The maritime tension in the South China Sea has been on the rise generally, while there have also been more frequent incidents between the Philippines and China in recent months.
Last month, the Philippine media reported that China had taken control of a traditional fishing atoll held by the Philippines.
The Quirino or Jackson Atoll, some 140 nautical miles west of the Philippines' Palawan Island, was taken into Chinese control, reports said.
China and the Philippines are waging a legal battle over territorial disputes in the South China Sea. The dispute is now before an arbitration court in The Hague.
The US too has US military facilities in Southeast Asia -- Philippines and Thailand. It also has stationed its Poseidon sub-hunters and electronic warfare platforms in Malaysia and Singapore.
The US, which has geopolitical interests in the region, has criticised the land reclamation, construction and militarisation activities undertaken by China in these islands.
However, Philippine officials say the military drills have nothing to do with the tensions in disputed waters.
"The Balikatan exercise is designed not to address a particular concern but the whole lump in the spectrum of warfare," Vice Admiral Alexander Lopez, the Philippine military's exercise director, said. "China is not part of the idea," he said.
Complex web of claims
In 2012, China and the Philippines faced off against each other in a tense maritime stand-off over Panatag (Scarborough) Shoal, which lies 100 km from the cost of Philippines and 500 km away from the cost of China's southern Hainan.
The Chinese then took control of the Shoal and forced the Philippines to release Chinese poachers who had been arrested from the area. The Chinese never left the shoal since then.
China angered the Philippines in 2012 when it created Sansha city, making it the administrative headquarters for the Paracels.