Philippine President Ferdinand Marcos Junior has vowed to support and modernize his country's Coast Guard. He called the service the "frontline" defending the Philippines' claims in the disputed South China Sea.

Marcos made his call at an event on Wednesday marking the 121st anniversary of the founding of the Philippine Coast Guard. He hailed the service for maintaining peace and order at sea.

He said, "You are the frontline in the defense of our maritime territory, in defense of our economic zones, in defense of our baselines."

The president urged the service to "ensure cleaner seas and secure maritime jurisdiction." He also said his administration is committed to modernizing the service.

The Coast Guard commissioned its most modern and largest multi-role vessels earlier this year. They routinely patrol the disputed waters.

Officials in Manila are increasingly concerned over Chinese activity in the South China Sea. Tensions have risen since Beijing introduced a law in February last year allowing its coast guard to fire weapons.

The Chinese have used water cannon against Philippine supply ships. In another incident, Chinese ships came dangerously close to a Philippine patrol boat in the disputed waters.