In his speech marking the 113th National Day of Taiwan at a ceremony in Taipei, Lai pledged to defend his nation's sovereignty in forceful remarks.
"The People’s Republic of China has no right to represent Taiwan,” he said. “I will also uphold the commitment to resist annexation or encroachment upon our sovereignty.”
The speech drew fury from Chinese Foreign Ministry spokesperson Mao Ning.
"It once again exposed that he is hellbent on advancing Taiwan independence and has the ill intention of heightening tensions in the Taiwan Strait for his selfish political interest,” Mao said at a briefing.
China has often reacted to more aggressive Taiwanese statements with large-scale military drills, though it wasn't immediately clear as of Thursday evening if Beijing would launch one.
A U.S. official told reporters on Wednesday ahead of Lai's speech that they were prepared for China to use the address as a pretext for large drills.
"We see no justification for a routine annual celebration to be used in this manner," the official said, according to Reuters. "Coercive actions like this against Taiwan and in the cross-Strait context, in our view, undermine cross-Strait stability."
Lai was inaugurated in May and delivered similar remarks, which prompted massive Chinese drills.
The Taiwanese leader maintains the status quo with China but has been clear he will stand up to any Chinese aggression.
The U.S. has informal relations with Taiwan but commits to supporting the country, including with arms.
Washington is preparing for a possible attack or blockade of Taiwan in 2027, the year Chinese leader Xi Jinping has told his forces to be ready for a potential invasion.
Vice President Harris, the Democratic presidential nominee, said in a "60 Minutes" interview on Monday that it was important to maintain the status quo.
"That includes supporting Taiwan's ability to defend itself," she said, dodging a question of whether the U.S. would defend the island nation in the event of a Chinese attack.
Read the full report at TheHill.com.
