MANILA >> The U.S. military is supporting Philippine operations in the South China Sea via a special task force, a U.S. embassy official said on Thursday, an initiative Manila said involves intelligence, surveillance and reconnaissance.

Task Force-Ayungin, named after the Philippine designation for the contested Second Thomas Shoal, was first mentioned this week by U.S. Defense Secretary Lloyd Austin during a visit to the Philippines.

“Task Force-Ayungin enhances U.S.-Philippine alliance coordination and interoperability by enabling U.S. forces to support Armed Forces of the Philippines activities in the South China Sea,” said U.S. embassy spokesperson Kanishka Gangopadhyay.

“This initiative aligns with multiple lines of cooperation between U.S. and Philippine forces,” he said, without elaborating on what kind of support the task force provides.

Defense ties between the Philippines and the United States have strengthened rapidly in the past few years, frustrating Beijing, which has a huge presence and vast claims in the South China Sea and sees Washington as an interfering power.

The United States says it has legitimate interests in ensuring peace and freedom of navigation in Asia’s most contested waters, through which more than $3 trillion of trade passes each year.

U.S. Indo-Pacific Command and China’s embassy in Manila did not immediately respond to a request for comment on the task force.

National Security Adviser Eduardo Ano said Philippine activities in the South China, including its missions to resupply troops at the Second Thomas Shoal, remain a “purely Philippine operation”.

“They are providing support to us, for example, ISR (Intelligence, Surveillance, Reconnaissance), maritime domain awareness, but on actual direct participation, its purely a Philippine operation,” Ano told reporters, referring to the U.S. task force.

The Philippine ambassador to the United States has previously said the Philippines has not asked Washington for support in resupplying its troops, and the U.S. was providing only “visuals” to help.

Confrontations between Beijing and Manila have been frequent of late, with China irked by Philippine resupply missions to soldiers on the Sierra Madre, a rusty warship that was intentionally grounded on the shoal 25 years ago to reinforce a territorial claim.

Tensions there have boiled over several times, with China’s coast guard accused of ramming vessels and using water cannon, injuring Filipino personnel.

China says the Philippines is intruding on its territory and claims indisputable sovereignty over the reef, located 1,300 km (808 miles) off its mainland and about 200 km from the Philippine coast.

The two countries have since reached a “provisional arrangement” for the resupply missions, with no altercations reported so far.