MANILA (REUTERS) - The Philippines has for the third time suspended a decision to scrap a two-decade-old Visiting Forces Agreement with the United States, its foreign minister said on Monday (June 14), amid a territorial dispute with China in the South China Sea.

Foreign Affairs Secretary Teodoro Locsin said the suspension would be for a further six months while President Rodrigo Duterte “studies, and both sides further address his concerns regarding, particular aspects of the agreement”.

The Philippines is a treaty ally of the US, and several military agreements are dependent on the VFA, which provides rules for the rotation of thousands of US troops in and out of the Philippines for war drills and exercises.

Mr Duterte last year notified Washington that he was cancelling the deal, which came amid outrage over a senator and ally being denied a US visa. The pact would have ended in August had Mr Duterte not extended its life for a third time.

His change of heart came as tensions increased between the Philippines and China over the disputed waters of the South China Sea, which China claims almost in whole.

Manila has repeatedly protested what it described as the "illegal" and "threatening" presence of hundreds of Chinese "maritime militia" inside its exclusive economic zone.

His decision also followed a US announcement that the Philippines was among countries that will receive part of the 80 million Covid-19 vaccines it is donating.

Ties between the US and its former colony have been complicated by Mr Duterte's rise to power in 2016 and his frequent condemnation of US foreign policy and embrace of China.

Mr Jose Manuel Romualdez, Manila's ambassador to Washington, told Reuters on June 3 that two-decades-old defence pact between the Philippines and the US had been revamped to make it "acceptable" and "mutually beneficial" to both countries.

Manila has in the past been unhappy about issues such as a lack of jurisdiction over US personnel found guilty of crimes in the Philippines and damage to the environment during maritime drills.

The Philippines, Brunei, China, Malaysia, Taiwan and Vietnam have competing claims of sovereignty in the South China Sea, through which goods worth more than US$3 trillion (S$4 trillion) pass every year.

The US Embassy in Manila did not immediately respond to a request for comment.