The navy vessels, along with 34 Chinese aircraft, were spotted near Taiwan in the 24 hours to 6:00 am (2200 GMT) Thursday, according to the defence ministry's daily tally.

Beijing has been holding its biggest maritime drills in years from near the southern islands of Japan to the South China Sea, Taiwan authorities said this week.

Around 90 Chinese warships and coast guard vessels have been involved in the exercises that include simulating attacks on foreign ships and practising blockading sea routes, a Taiwan security official said Wednesday.

There has been no announcement by Beijing's army or Chinese state media about increased military activity in the East China Sea, Taiwan Strait, South China Sea or Western Pacific Ocean.

However, a recent Pacific tour by Taiwanese President Lai Ching-te that included two stops in US territory drew fury from Beijing, which claims the democratic island as part of China's territory.

The security official said that China began planning the massive maritime operation in October and aimed to demonstrate it could choke off Taiwan and draw a "red line" ahead of the next US administration.

The sea drills were "significantly larger" than Beijing's maritime response to then-US House speaker Nancy Pelosi's visit to Taipei in 2022, the security official said. Those war games were China's largest-ever around Taiwan.

Taiwan's foreign ministry said Wednesday that China's increased military activity around the island was evidence that Beijing was a "troublemaker".

But China's foreign ministry -- whose spokesperson neither confirmed nor denied that drills were taking place -- directed blame at Taiwan.

The de facto US embassy in Taiwan said Thursday it was monitoring "with concern" Beijing's People's Liberation Army (PLA) activity near the island and in the region.

While Beijing had not announced major drills in response to Lai's trip, Chinese military activity was "elevated", which was "consistent with levels we have seen during other large exercises," a spokesperson for the American Institute in Taiwan said.

- Airspace back to 'normal' -

James Char, an expert on China's military at Singapore's Nanyang Technological University, said Beijing's silence "serves as a way of demonstrating that the Taiwan Strait as well as the waters and airspace around the island falls under Chinese sovereignty -- hence unnecessary to announce (the drills) to the world".

"This is another means by the mainland to force its position upon others," Char told AFP, though he did not rule out Chinese confirmation at a later date.

Taiwan said Monday that the PLA had reserved airspace off the Chinese coast until Wednesday.

Vietnam-based maritime security analyst Duan Dang told AFP Thursday that aviation data showed the airspace zones had "fully returned to normal".

Taiwan lives under the constant threat of invasion by China, which has not ruled out using force to bring the island under its control.

Beijing has ramped up the deployment of fighter jets and warships around the island in recent years, and also opposes any international recognition of self-ruled Taiwan -- especially when it comes to official contact between Taipei and Washington.

Lai spoke last week with Republican House Speaker Mike Johnson in addition to his two recent stopovers on US soil.

The defence ministry's tally of Chinese warships on Thursday was the highest since May 25, when 27 navy vessels were detected during Chinese military drills held days after Lai's inauguration.

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