Albert del Rosario, who was at the forefront of the South China Sea dispute as President Benigno Aquino III foreign secretary, passed away Tuesday.

The Department of Foreign Affairs said he was on his way to San Francisco when he passed away. He was 83.

He opposed China’s occupation of the Scarborough Shoal which led to government’s bringing the case to the Arbitral Tribunal at The Hague.

The tribunal upheld the Philippines’ claim in 2016 but China has not recognized the ruling. DMS