Defense chiefs from Japan, Australia and the United States have pledged to bolster trilateral cooperation and further align their security strategies amid growing tensions with China, Russia and North Korea.

"Today, the international community is faced with these severe security environments due to Russia's aggression against Ukraine, China's unilateral change of status by force in the South and East China seas, and the remarkable development of North Korea's nuclear and missile-related technologies, among others," Defense Minister Yasukazu Hamada was quoted as saying during the talks in Hawaii on Saturday. "The foundation of the international order has been undermined."

But it was China, in particular, that appeared to loom large at the talks.