China has no reason to react harshly to Taiwan president US transit: White House

China should not use Taiwanese President Tsai Ing-wen's transit through Los Angeles and New York City to react harshly against Taipei, the White House said Wednesday.

Tsai is transiting through the US ahead of her upcoming visit to Latin America. National Security Council spokesperson John Kirby said her travel "is consistent with our long standing unofficial relationship with Taiwan, and it is consistent with the United States' One China policy, which remains unchanged."

"It is Taiwan's decision to make these transits based on their own travel. Transits are not visits. They are private, and they're unofficial," he told reporters on a virtual briefing.

"The People's Republic of China should not use this transit as a pretext to step up any aggressive activity around the Taiwan Strait. The United States and China have differences when it comes to Taiwan. But we have managed those differences for more than 40 years," he added.

Tsai has transited through the US six times since taking office in 2016, according to the US.

China earlier Wednesday warned of unspecified retaliation if Tsai meets with US House Speaker Kevin McCarthy during her travels amid speculation that a sit-down could be in the offing when she travels to McCarthy's home state of California. A meeting is tentatively scheduled for April 5, according to multiple reports.

Beijing will "take resolute countermeasures" against such an event, Zhu Fenglian, spokeswoman for the Taiwan Affairs Office of China's State Council said.

Tsai, 66, left the capital of Taipei for a 10-day trip to Central America on Wednesday.

She will make her first stopover in New York before flying to Central America. She is expected in Los Angeles on the return leg of her trip.

An unannounced trip to Taiwan by McCarthy's predecessor, Nancy Pelosi, in August triggered an unprecedented response from China, which launched military operations around Taiwan, a self-governing island of 24 million sitting across the Taiwan Strait from mainland China.

China sent 16 aircraft and four vessels around Taiwan on Wednesday as Tsai flew out for her first overseas trip in three years as the coronavirus pandemic had forced border closures.

Taiwan's Defense Ministry said 11 Chinese aircraft entered the southwest Air Defense Identification Zone, which Beijing does not recognize.

China views Taiwan as a breakaway province, though the island has ruled itself since 1949 and has established diplomatic relations with a dozen nations. Beijing has vowed to reunify it, including by force if it deems such action necessary.