(Bloomberg) -- Vice President Kamala Harris said the Biden administration intends to deepen America’s unofficial ties with Taiwan, a fresh US warning to China that she delivered in a speech from the deck of a US warship in Japan. 

“Taiwan is a vibrant democracy that contributes to the global good -- from technology to health, and beyond, and the United States will continue to deepen our unofficial ties,” Harris said Wednesday, according to excerpts released by the White House in advance.  

She criticized China, saying Beijing “has challenged freedom of the seas” and “has flexed its military and economic might to coerce and intimidate its neighbors.”

Harris added that many have witnessed “disturbing behavior in the East China Sea and in the South China Sea, and most recently, provocations across the Taiwan Strait.”

Biden administration officials are increasingly concerned about China’s moves to expand its economic and military influence and its intentions toward Taiwan, the self-governed island that Beijing regards as part of its territory. President Joe Biden has said repeatedly that US troops would defend Taiwan if China invades, including in an interview on “60 Minutes” earlier this month.

“The United States believes that peace and stability in the Taiwan Strait is an essential feature of a free and open Indo-Pacific,” Harris said aboard the USS Howard, an Arleigh Burke-class destroyer.

Biden’s Vow to Defend Taiwan Makes US Policy Shift Explicit 

The vice president is on a four-day trip to Japan and South Korea intended to demonstrate US commitment to allies in the region -- and to burnish her foreign policy credentials.

Harris’s trip will set the stage for Biden’s visit to the region later this year, where he’s expected to meet Chinese President Xi Jinping and speak with allies about both efforts to denuclearize the Korean Peninsula and address rising tensions over Taiwan.

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