Taiwan's prime minister has warned that a "return" to China is not an option.
Cho Jung-tai's remarks came hours after President Xi Jinping mentioned the issue on a phone call with his US counterpart Donald Trump.
Mr Xi had described Taiwan's return to mainland China as "an integral part of the post-war international order".
But the island's democratically elected government has rejected this - describing Taiwan as a "fully sovereign and independent country".
"For the 23 million people of our nation, 'return' is not an option - this is very clear," Mr Cho added.
China has offered Taiwan a "one country, two systems" model, but this position is not supported by any mainstream political party.
Meanwhile, relations between Beijing and Tokyo recently plunged to fresh lows after Japan's prime minister suggested any attack on Taiwan would spark a military response.
Sanae Takaichi's remarks were swiftly denounced by China's foreign ministry, which said Japan had "crossed a red line that should not have been touched".
Sun Yun from the Stimson Centre thinktank said: "My best guess is China is worried about the escalation with Japan.
"The reference to Taiwan and the post-World War II order directly points to the spat with Japan over Taiwan."
The US has not taken a side when it comes to Taiwan's sovereignty but is opposed to any use of force to seize the territory.
Mr Trump's administration has also been ambiguous over whether it would deploy US troops if war broke out in the Taiwan Strait.
Yesterday, Taiwan's defence ministry spotted a single balloon from China flying over the strait and claims this is part of a campaign of harassment by Beijing.
Chinese officials have previously dismissed these complaints, arguing the balloons are for meteorological purposes.
In other developments, Mr Trump has confirmed that he will visit Beijing in April - with Mr Xi set to travel to Washington for a state visit later in 2026.
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