The United States is due to open a new embassy in Taiwan on Tuesday, but plans to send a junior minister to avoid igniting a diplomatic row with China.
Beijing, which does not recognise Taiwan as a state independent from China, has mounted a concerted campaign over the past two years to lure away the few remaining countries that recognise Taipei.
The US, a major backer of Taipei, made a $1.42 billion arms deal with the island state in 2017, and spent $250 million (£187 million) on the new de facto embassy.
However, in order to assuage China’s anger, the US will not send a top-level official to the opening of its de facto embassy in Taiwan on Tuesday, a signal that Donald Trump does not want to provoke Beijing.
Speculation had mounted earlier this year that national security adviser John Bolton would be sent to the opening of the American Institute in Taiwan (AIT).
At a glance | The One China policy
Instead, Marie Royce, assistant secretary of state for educational and cultural affairs, will open the AIT, Washington said. Beijing views Taiwan as a breakaway province, which will be reunited with the mainland by force if necessary.
The US gave up official diplomatic ties with Taipei in 1979 when it switched recognition to Beijing, but Washington remains a powerful ally of Taiwan.
The new AIT offices are being unveiled amid heightened concerns in Beijing over increasing US involvement in Taiwan.
Mr Trump in March signed the Taiwan Travel Act, which will allow more official visits between the US and Taipei.
Washington also agreed to help Taipei build its own submarines, a move which Chinese media said made war "more probable" between China and Taiwan.
The US is embroiled in a major trade row with China, but is keen to avoid a diplomatic fallout as it needs Beijing’s help to solve the North Korea nuclear issue.
Taiwan, meanwhile, has become increasingly marginalised on the international stage with the loss of diplomatic allies who previously recognised the government of the self-ruled island, but have now switched to Beijing.
The West African state of Burkina Faso said it was severing ties with Taiwan last month, following similar moves from the Dominican Republic, Sao Tome and Principe and Panama.
Additional reporting by Christine Wei