MANILA - The abandonment of fishermen in the boat-ramming incident in the West Philippine Sea is a violation of international law, Presidential Spokesperson Salvador Panelo said Friday.

The United Nations Convention on the Law of the Sea mandates nations to rescue people of any nationality who are in distress at sea, Panelo told ANC's Early Edition.

"The act happened in the high seas. We're angry at the act of abandonment. It's in violation of UNCLOS," he said.

"You don't even need an international provision on that. It's a human act of lending a hand to somebody in distress," he said.

The Philippines has filed a diplomatic protest after a Chinese vessel rammed a Philippine fishing boat and left 22 fishermen in open waters.

• PH files diplomatic protest vs China over West PH Sea ‘hit and run’

President Rodrigo Duterte has yet to comment on the issue, but Panelo said the "cautious" chief executive is just making "calibrated responses."

"We're not politicizing the incident," he said.