China building capacity to strike Taiwan: Taiwanese official

China is building its capacity to rapidly turn military drills into a full-out attack, a senior Taiwan security official said in an assessment of China's most recent military drill around the island.

China, which views democratically governed Taiwan as its own territory, staged large-scale drills on Monday that it said were a warning to "separatist acts" following last week's national day speech by Taiwan President Lai Ching-te.

Taiwan has for the past five years complained of almost daily Chinese military activities around the island, including at least four rounds of major war games and regular "joint combat readiness patrols".

"They are increasing the building up of their capacity to turn military exercises into a conflict," the official said at a briefing in Taipei, requesting anonymity to be able to speak more frankly.

Taiwan reported a record 153 Chinese aircraft took part in the drills, and the official added an unprecedented 25 Chinese navy and coast guard boats also approached close to Taiwan's 24-mile (39-km) contiguous zone.

"They approached very close to Taiwan. They increased their pressure on Taiwan and squeezed Taiwan's response time," the official said. "This drill presented more of a threat than ever before to Taiwan."

The official said during the drill, China launched two missiles towards an unspecified inland area, without providing further details.

"Although they did not fire missiles towards Taiwan this time, they did practice missile launches," the official said.

China's defence ministry did not immediately respond to a request for comment. On Monday, it vowed to take further action as needed against Taiwan, while on Wednesday China's Taiwan Affairs Office said Beijing will never commit to renouncing the use of force over Taiwan.

The Taiwan official said their own intelligence had detected signs of China's drills ahead of time and deployed assets including mobile missile launchers to strategic spots before Beijing announced the war games around dawn on Monday.

Lai and his government reject Beijing's sovereignty claims saying only Taiwan's people can decide their future. Lai has repeatedly offered talks, but he has been rebuffed by China.