Taiwan President Tsai Ing-wen is set to leave for the United States, a stop on her way to firm ties with Guatemala and Belize after China snapped up another of the self-ruled island's few diplomatic allies last week.
"We are calm and confident, will neither yield nor provoke," Tsai said on Wednesday at Taiwan's main international airport at Taoyuan, adding that external pressure will not stop Taiwan's determination to go out into the world.
According to international media reports, after first visiting New York, Tsai will continue her 10-day trip by meeting her Guatemalan counterpart Alejandro Giammattei and Belize Prime Minister John Briceno in their respective countries.
She will then stop in Los Angeles on her way back to Taiwan.
US House Speaker Kevin McCarthy said he will meet Tsai in California, a move protested by China's Taiwan Affairs Office, which called the meeting "a provocation".
"This so-called transit by the Taiwan leader is essentially a provocation that aims to seek independence relying on the US," said Zhu Fenglian, a spokesperson.
Last year, a visit by McCarthy's predecessor to Taiwan sparked an angry response from Beijing, with the Chinese military conducting drills at an unprecedented scale around the island. Taipei said the exercises were preparation for an invasion.
Taiwanese authorities have not confirmed the meeting with McCarthy or Tsai's itinerary while in New York.
Belize and Guatemala are among just 13 countries that officially recognise democratic Taipei over Beijing, after Honduras opened diplomatic relations with China on Sunday.
China claims the self-ruled island as part of its territory and under its "One China" principle, no country may maintain official ties with both Beijing and Taipei.
In response to Beijing, a senior US official said on Wednesday that China should not "overreact" and use a stopover as a "pretext" for aggression against the democratically ruled island of Taiwan.
"There's absolutely no reason for China to use that as a pretext to overreact or to engage in further coercion directed at Taiwan," a senior administration told reporters, speaking on condition of anonymity.
"We're going to carry out a transit that is fully consistent with that policy and decades' worth of practice," the official said, adding that Beijing "will not pressure the US government to alter our longstanding practice" on such visits.