Seventy-one Chinese air force aircraft including fighter jets and drones entered Taiwan’s air defence identification zone in the past 24 hours, the island’s government said on Monday, the largest reported incursion to date. The incursion included 43 Chinese aircraft that crossed the Taiwan Strait’s median line, an unofficial buffer between the two sides that lies within the defence zone, Taiwan’s defence ministry said in a report, as Beijing continues military activities close to the island. Taiwan’s official Central News Agency said it was the largest Chinese air force incursion to date, although there was no sense of alarm on the island. China’s military harassment of self-ruled Taiwan, which Beijing claims to own, has intensified in recent years, and the Communist party’s People’s Liberation Army has sent planes or ships toward the island on a near-daily basis. China said it had conducted “strike drills” in the sea and airspace around Taiwan on Sunday in response to what it said was provocation from the democratically governed island and the US. Taiwan’s president, Tsai Ing-wen, speaking at a military ceremony on Monday, reiterated the need for Taiwan to boost its defence capacity due to “the continuous expansion of authoritarianism”, although she made no mention of the latest military activity. “The more preparations we make, the less likely there will be rash attempts of aggression. The more united we are, the stronger and safer Taiwan would become,” Tsai told the assembled officers. Between 6am Sunday and 6am Monday, 47 of the Chinese planes crossed the median of the Taiwan Strait, an unofficial boundary once tacitly accepted by both sides, according to Taiwan’s defence ministry. Among the planes were 18 J-16 fighter jets, 11 J-1 fighters, six Su-30 fighters and drones. Taiwan said it monitored the Chinese moves using its land-based missile systems and navy vessels. “This is a firm response to the current US-Taiwan escalation and provocation,” said Shi Yi, spokesperson for the Chinese army’s eastern theatre command, which announced joint combat patrols and strike drills in the waters around Taiwan. Shi was referring to the US defence spending bill, which calls China a strategic challenge. With regard to the Indo-Pacific region, the legislation authorises increased security cooperation with Taiwan and requires expanded cooperation with India on emerging defence technologies, readiness and logistics. China’s military has often used large military exercises as a demonstration of force in response to US government actions in support of Taiwan. It conducted large live-fire military exercises in August in response to US House speaker Nancy Pelosi’s visit to Taiwan. Beijing views visits from foreign governments to the island as de facto recognition of the island as independent and a challenge to China’s claim of sovereignty.