The two-week course on the Philippines' southern island of Mindanao comes as part of a regional effort to boost law enforcement cooperation as fears of maritime conflict with China grow.

There have been frequent clashes or tense standoffs between Philippine and Chinese vessels in the strategic waterway, as well as recent incidents involving Vietnamese and Indonesian vessels.

"Together, we reaffirm our commitment to ensuring that our maritime sovereignty remains a zone of peace, safety and prosperity for all," Philippine Coast Guard District Commander Rejard V. Marfe said in a statement released by the US embassy.

Marfe called the January 13-24 training "invaluable in ensuring that we are better equipped to address maritime threats", though the statement made no mention of China.

The training covered safe vessel boarding at sea, maritime law, evidence collection and preservation, safety and risk mitigation and arrest techniques, according to the statement.

The Australian Border Force joined the coast guard, customs enforcers and fisheries surveillance officials at the training as observers.

China has stepped up expansion of its naval forces in recent years as it seeks to extend its reach in the Pacific and challenge a US-led alliance.

In recent months, China has deployed navy and coast guard vessels to bar the Philippines from strategically important reefs and islands in the South China Sea.

In October, Hanoi accused Beijing of a "brutal" attack in which it said 10 Vietnamese fishermen were beaten with iron bars and robbed of thousands of dollars worth of fish and equipment.

And the same month, Indonesia said it drove a Chinese coast guard ship from contested waters in the South China Sea three times in a week.