Speaking outside the Presidential Office in Taipei before thousands of people including foreign diplomats, Lai said Taiwan "cherishes peace" and will "not give up our freedom." He added: "We are open to exchanges, but will not accept subordination."
Taiwanese fighter jets and two Chinook helicopters carrying giant Taiwan flags flew over the capital ahead of the speech, which marked the 115th anniversary of the 1911 uprising that toppled China's last imperial dynasty.
Lai's government has set aside more than 3 percent of gross domestic product for defence in 2027. The record allocation comes as Beijing continues to pressure the island militarily. According to Taiwan's defence ministry, 21 Chinese military aircraft and seven navy ships were operating around Taiwan in the 24 hours to 6 a.m. Saturday, with 13 of the aircraft crossing the median line in the Taiwan Strait.
"Peace cannot rely solely on wishes, and tolerance cannot become a pretext for aggressors to encroach ever further," Lai said. He described China's actions as "grey-zone activities" that stop short of open war but try to alter the status quo across the strait.
Lai urged democracies in the Indo-Pacific to join forces to preserve regional peace and stability. He also welcomed talks between the United States and China but insisted "there must be respect for the right of the people of Taiwan to exist."
Eswatini King Mswati III and Indiana Lieutenant Governor Micah Beckwith were among foreign guests offering congratulations, Lai's office said.