The Philippines government has been behind the intensifying tensions in the South China Sea, a former diplomat for the country said on Wednesday.

"China has been for the negotiations all along, but from the beginning we are not," said Alberto Encomienda, former secretary-general of the Maritime and Ocean Affairs Center of the Philippines' Foreign Affairs Department.

Although the Foreign Affairs Department has said it conducted more than 50 consultations and negotiations with China from 1995 to 2012, those did not happen, said the diplomat, who was then in charge of the negotiations.

Encomienda said China "has been sending quiet feelers to improve relations".

"Prior to 2005's APEC (summit), China sent two delegations to the Philippines, and invited delegations from the House of Representatives to Beijing. We never gave this much attention. After the summit, China sent feelers to the Philippines again. We never responded," he said.

Encomienda also said that China should not be demonized over the South China Sea issue, since it was the Philippines that first engaged in reclamation activities in the sea, building airstrips on China's Zhongye Island.

He said the airfield on Zhongye Island "was built on top of live coral reefs".

Encomienda also lashed out at the United States for its military presence in the South China Sea and what he described as its purpose to set the Philippines against China on the issue.

After President Benigno Aquino III's first state visit to the United States in 2010, "everything that came up as the Philippines' South China Sea position has something to do with 'rule-based' and 'legal framework'. But these are a rule basis determined by the US," said Encomienda.

The former diplomat said the Philippines "is in urgent need of an independent foreign policy".