Top diplomats from ¡°the Quad¡± group of nations on Monday pledged to boost maritime security in the Indo-Pacific region as they criticized what they called the ¡°militarization¡± of the disputed South China Sea, in a move seen as targeting China¡¯s growing assertiveness in the strategic waterway.

In a joint statement following a meeting in Tokyo, the officials from Australia, Japan, India and the United States expressed ¡°serious concern¡± about ¡°coercive and intimidating maneuvers,¡± the ¡°dangerous use¡± of coast guard and maritime militia vessels, as well as efforts to ¡°disrupt¡± other countries¡¯ offshore resource exploitation activities.

The criticism came as the Quad diplomats sought to present a united front amid heightened tensions between China and the Philippines, a U.S. ally, over maritime disputes.