The foreign ministers of the Quadrilateral Security Dialogue countries on Monday expressed “serious” concern over the situation in the East and South China Seas, according to a joint statement issued at the end of their meeting in Tokyo.

Japanese Foreign Minister Yoko Kamikawa hosted her counterparts Antony Blinken from the US, Penny Wong from Australia and Subrahmanyam Jaishankar from India.

Without naming China, the four foreign ministers reiterated their “strong opposition to any unilateral actions that seek to change the status quo by force or coercion.”

The US-led Quadrilateral Security Dialogue, commonly known as Quad, is a loose security alliance between the four nations.

The statement also expressed “serious concern about the militarization of disputed features, and coercive and intimidating maneuvers in the South China Sea.”

“We also express our serious concern about the dangerous use of coast guard and maritime militia vessels, the increasing use of various kinds of dangerous maneuvers, and efforts to disrupt other countries’ offshore resource exploitation activities,” it added.