The defense ministers of the United States, Australia and Japan plan to deepen their military cooperation amid China's growing ambitions.
"We are deeply concerned by China's increasingly aggressive and bullying behavior in the Taiwan Strait and elsewhere in the region," US Secretary of Defense Lloyd Austin said Saturday at a meeting with defense ministers from Australia and Japan at US Pacific Military Headquarters in Hawaii.
China is trying to shape the world around it "in ways we've never seen before," said Australian Defense Minister Richard Marles.
Washington announced an $810 million aid package for the Pacific island nations on Thursday.
With this, the United States wants to strengthen its diplomatic presence in the region.
On the same day, Vice President Kamala Harris visited Japan and South Korea, where she said the United States would act without fear or hesitation throughout Asia, including across the Taiwan Strait.
A few days earlier, US Secretary of State Antony Blinken had called for "peace and stability" in the Taiwan Strait during a meeting with his Chinese counterpart Wang Yi on the fringes of the general debate at the UN General Assembly.
Since the split between China and Taiwan in 1949, Beijing has regarded Taiwan as a breakaway territory and has claimed the strait between mainland China and the island.
Tensions between Beijing and Taipei, and also between Beijing and Washington, had grown following a visit to Taiwan by top politician Nancy Pelosi in August.
China's army then held its largest military maneuvers to date in the waters around the island, shooting down missiles in the process.
Taiwan also held exercises and presented new combat aircraft.