"The PRC's moves threaten to undermine security, and stability, and prosperity in the Indo-Pacific," Austin said, using the acronym to refer to the country by its official name, the People's Republic of China.

He listed a series of areas where China is ‘muscling its neighbours’, including sending large numbers of warplanes into the skies near Taiwan, dangerously intercepting the patrol planes of US allies and illegal fishing operations that "plunder the region's provisions."

Taiwan played a key role in Austin's address, as it did during a meeting he had with Chinese defence minister Wei Fenghe on Friday evening.

During that meeting, both sides accused the other of trying to change the decades-long status quo over the self-governed democracy of Taiwan and its 23 million people.

"We're determined to uphold the status quo that has served this region so well for so long," Austin said.

Under the ‘One China’ policy, the US acknowledges China's position that Taiwan is part of China, but has never officially recognised Beijing's claim.

Austin said the US was acting appropriately in the region but China was operating differently.

"We've witnessed a steady increase in provocative and destabilising military activity near Taiwan,” he said.

“That includes PLA aircraft flying near Taiwan in record numbers in recent months - and on a nearly daily basis," he said, referring to flights of Chinese warplanes into Taiwan's air defence identification zone.

Austin’s accusations against China went well beyond Taiwan.

"In the East China Sea, (China's) expanding fishing fleet is sparking tensions with its neighbours,” he said.

“And China is using outposts on man-made islands bristling with advanced weaponry to advance its illegal maritime claims," Austin said.

"We're seeing (Chinese) vessels plunder the region's provisions, operating illegally within the territorial waters of other Indo-Pacific countries.”

Austin also pointed to Russia's invasion of Ukraine as an example of the "turmoil" that can ensure when nations veer from international law.

"It's a preview of a possible world of chaos and turmoil that none of us would want to live in."

How the Ukraine war can affect Pacific security was also brought to the forefront by Japanese prime minister Fumio Kishida.

"Ukraine today may be East Asia tomorrow," Kishida said, adding that to ensure its security Tokyo would be substantially increasing its defence budget.

"We will not rule out any options, including so-called counterstrike capabilities, and will realistically consider what is necessary to protect the lives and livelihoods of our people," he said.

Austin noted the bigger roles that Japan and other allies are playing in US Pacific policies. One of these partners is India, which along with Japan and Australia is a member of the informal Quad alliance.

“We believe that India’s growing military capability and technological prowess can be a stabilising force in the region." Austin said.

In a key move in the Pacific Islands, where China has been making a push to make new security and economic agreements with small island states, Austin said Washington was making "unprecedented" US Coast Guard investments.

This includes for the first time permanently stationing a Coast Guard cutter in the region for the first time.

Zhang, said the US strategy in the Indo-Pacific is to "maintain its hegemony."

"The United States is trying to form a small circle in the Asia-Pacific region by roping in some countries to incite against some other countries," Zhang said.

He accused the US of trying to "push the Indo-Pacific region into the trap of geopolitical games and camp confrontation."

Austin said the Biden administration is prepared to step up to be a leader and a guarantor of the free and open Indo-Pacific.

"Big powers carry big responsibilities," he said. "And so we'll do our part to manage these tensions responsibly, to prevent conflict, and to pursue peace and prosperity."