Taiwanese Vice President William Lai took off for a sensitive journey to the US on Saturday, in a move that has raised fears it could spur more Chinese military drills near the democratically-governed island.

Lai is expected to stop in New York and San Francisco before continuing the trip to Paraguay. The Latin American nation is one of only a handful of countries that still maintain formal diplomatic relations with Taiwan.

"Departing soon for #Asuncion to attend [president-elect Santiago Pena's] inauguration and convey to him and the people of #Paraguay the best wishes of [Taiwan]," Lai posted on X, the platform formerly known as Twitter. "[E]xcited to meet with #US friends in transit."

Lai, a member of the center-left Democratic Progressive Party, is a frontrunner ahead of Taiwan's presidential vote next year.

China decries visit, while Taiwan says it's 'nothing special'

Mainland China has condemned the stopovers by Lai and said the politician advocates Taiwanese separatism. China views Taiwan as part of its territory, and believes a trip to the US grants Taiwan an aura of legitimacy.

The Chinese Foreign Ministry has called on Washington to "abide by the One-China principle... and to stop official exchanges between the US and Taiwan."

As part of its One China policy, the US acknowledges the People's Republic of China as the sole legitimate government of China. At the same time, the US informally helps Taiwan and provides aid to the island as aligned with the 1979 Taiwan Relations Act.

Taiwan, meanwhile, has defended the visit and said Taiwanese vice presidents have journeyed to the US several times before. Taiwanese Foreign Ministry Spokesman Jeff Liu said Lai's stopover is "nothing special."

Taiwanese President Tsai Ing-wen met with US House Speaker Kevin McCarthy during a stopover in the US in April, drawing similar ire from Beijing.

But the visit by Lai to the US may end up increasing tensions in the Taiwan Strait. Taiwanese authorities contend that China could use Lai's stopovers in the US as a reason for more military maneuvers in the region.