Beijing has flown growing numbers of its warplanes near the island, and US President Joe Biden last month appeared to break with decades of US policy when he said Washington would defend Taiwan militarily if it is attacked by China.
A day after clashing with China’s defence minister over Taiwan in their first face-to-face talks, Austin called out Beijing’s “growing coercion” towards the island.
“We’ve witnessed a steady increase in provocative and destabilising military activity near Taiwan,” Austin told the Shangri-La Dialogue security summit in Singapore.
“That includes (Chinese military) aircraft flying near Taiwan in record numbers in recent months, and nearly on a daily basis,” he said.
“We categorically oppose any unilateral changes to the status quo from either side,” he added.
“Our policy hasn’t changed. Unfortunately that doesn’t seem to be true for (China)”.
On Friday, the issue was top of the agenda at talks between Austin and China’s Defence Minister Wei Fenghe on the sidelines of the summit.
Wei warned Austin that “if anyone dares to split Taiwan from China, the Chinese army will definitely not hesitate to start a war no matter the cost”, according to Chinese officials.
He also vowed that Beijing would “smash to smithereens any ‘Taiwan independence’ plot and resolutely uphold the unification of the motherland”, according to the Chinese defence ministry.
Tensions over Taiwan have escalated in particular due to increasing Chinese aircraft incursions into the island’s air defence identification zone (ADIZ).
Last year, Taiwan recorded 969 incursions by Chinese warplanes into its ADIZ, according to an AFP database -- more than double the roughly 380 carried out in 2020.
Biden’s comments on defending Taiwan militarily came in response to a question during a visit to Japan last month.
The White House has, however, since insisted its policy of “strategic ambiguity” over whether or not it would intervene has not changed.
Austin is the latest senior US official to visit Asia as Washington seeks to shift its foreign policy focus back to the region from the Ukraine war.
Beyond Taiwan, China and the United States have been locked in a range of other disputes.
They have been at loggerheads over Russia’s invasion of Ukraine, with Washington accusing Beijing of providing tacit support for Moscow.
China has called for talks to end the war, but has stopped short of condemning Russia’s actions and has repeatedly criticised American arms donations to Ukraine.
China’s expansive claims in the South China Sea have also stoked tensions with Washington.
Wei will Sunday address the summit, which runs from 10 to 12 June.
The event is usually annual but is taking place this year for the first time since 2019 after twice being postponed due to the Covid-19 pandemic.