Chinese J-11 fighter jets (AP)

Chinese air jets crossed the median line, also known as the "buffer zone", of the Taiwan Strait on Friday and conducted patrol missions, Taiwan's Defense Ministry said.

Taiwan's President Tsai Ing-wen arrived on Wednesday in New York for a transit visit on her way to Central America, where she is expected to meet with US House Speaker Kevin McCarthy on her way back, in California.

Beijing warned on Wednesday that it was vehemently opposed to any meeting between Tsai and McCarthy and vowed to take "resolute measures to fight back" if the meeting takes place. The United States responded by saying that China should not use Tsai's stopover as a pretext to "act aggressively" around the Taiwan Strait.

Nine Chinese aircraft crossed the median line from the north, center, and south, the Defense Ministry said, while Taiwan's military deployed jets and ships to monitor the situation while sticking to "not escalating conflicts or causing disputes," the Ministry added.

"The communist military's deployment of forces deliberately created tension in the Taiwan Strait, not only undermining peace and stability, but also has a negative impact on regional security and economic development," it continued while condemning what it described as "irrational actions".

During her New York stopover, Tsai accused China of being behind the escalating tensions.

"China deliberately raises tensions, but Taiwan always responds cautiously and calmly, so that the world can see that Taiwan is the responsible party in cross-Strait relations," she said during an event held by the Hudson Institute.

The Taiwanese President also met with Democratic Congressman Hakeem Jeffries according to reports and is expected to meet more US officials during her trip.

Tsai's trip to Belize and Guatemala follows Honduras' decision this month to open diplomatic relations with Beijing, leaving the two central American countries along with 13 other countries that have official ties with Taipei. Responding to the decision, Taiwan accused China of using "coercion and intimidation" to lure away its allies.

'Nothing unusual'

China's aircraft only "slightly" passed across the median line, a Taiwan official told Reuters, adding that Chinese ships were operating as usual

During the former US House Speaker Nancy Pelosi's visit to the island last August, China carried out massive military exercises around Taiwan after repeatedly warning Washington against this visit which is considered a breach of the "One China" policy.

China's drills were a "charm offensive" toward foreign political leaders and business personnel, the Taiwanese official said, adding that Beijing is unlikely to conduct such massive exercises again, confirming that increased military tensions between China and Taiepei would send "conflicting messages" to the world.

"Having said that, we have made all preparations in case China reacts irrationally," the official said. "The more the international community pays attention to Taiwan, the more upset they get."

Taiwan's Prime Minister said on Friday that Taiwan is a "democratic country" and has the right to engage with the whole world.

"I hope that China will not find pretext to provoke," he told reporters when asked about China's warnings.

"China's authoritarian expansion will in fact cause unnecessary trouble, so we here again make this call, hoping that China can reduce its provocative actions."