TAIPEI: Taiwan will not be afraid nor back down in the face of authoritarian threats, the island's vice president told supporters on a U.S. visit that Beijing has condemned, while reiterating a willingness to talk to China.

William Lai, also frontrunner to be Taiwan's next president at January elections, is in the United States on what is officially a transit stop on his way to Paraguay for the inauguration of its new president. Paraguay is one of only 13 countries to maintain formal ties with the Chinese-claimed island.

Taiwan and the United States both say the stopovers, including one in San Francisco on the way back, are routine, but China has denounced them and called Lai a separatist "troublemaker".

Lai told a supporters lunch in New York on Sunday that "if Taiwan is safe, the world is safe, if the Taiwan Strait is peaceful, then the world is peaceful", according to Taiwan's presidential office.

"No matter how great the threat of authoritarianism is to Taiwan, we absolutely will not be scared nor cower, we will uphold the values of democracy and freedom," he said.

China considers Taiwan its most important diplomatic issue, and is a constant source of friction between Beijing and Washington, which is the island's most important international backer and arms supplier.

China has a particular dislike of Lai, who has previously described himself as a "practical worker for Taiwan independence", a red line for Beijing which has never renounced the use of force to bring the island under its control.

WILLING TO TALK

Lai, who has pledged to maintain peace and the status quo, reiterated in New York that on the basic principle of dignity and parity he was "very willing" to talk to China and seek peace and stability.

But Lai said he will protect Taiwan's sovereignty, that only Taiwan's people can decide their future and that the Republic of China - Taiwan's formal name - and the People's Republic of China are "not subordinate to each other".

Lai's speech was attended by Ingrid Larson, managing director of the American Institute in Taiwan, a U.S. government-run non-profit that carries out unofficial relations with Taiwan.

Both Taipei and Washington are aiming for the U.S. stopovers to be low-key, and have called on China not to take any provocative action in response.

Still, Taiwanese officials say China is likely to launch military drills this week near Taiwan, using Lai's U.S. stopovers as a pretext to intimidate voters ahead of a next year's election and make them "fear war".

On Monday, the Eastern Theatre Command of China's People's Liberation Army, which has responsibility for the area around Taiwan, showed pictures on its WeChat account of troops practicing storming a beach, though did not give the location, timing or specifically mention Taiwan.

It said the soldiers guided armoured vehicles "to the enemy frontline positions and launched a fierce attack".

China carried out war games around Taiwan in April after Taiwan President Tsai Ing-wen returned from California where she met U.S. House Speaker Kevin McCarthy while also on a transit on her way back from Central America.