Taiwan's most senior defense official says the nation's air force pilots—under pressure from daily Chinese military flights near the island—will adhere to a strict "never strike first" policy, even if provoked.

Chiu Kuo-cheng, who heads Taiwan's Ministry of National Defense, attended a budget review on Wednesday as his department tried to justify 240 billion New Taiwan dollars ($8.56 billion) in special spending for more anti-ship and land-based cruise missiles.

Questions by members of the Taiwanese parliament's Foreign and National Defense Committee and Finance Committee revolved around China's rapidly expanding military capabilities, as well as the recent surge in People's Liberation Army aircraft conducting training missions southwest of the island.

Chiu, 68, said tensions across the Taiwan Strait were in the "most severe" state of his 40-year military career. This was being felt by the armed forces and the public alike, he said.

Asked about the risk of miscalculation amid the increase in Chinese military maneuvers, which Taiwan's air force is tasked with intercepting, Chiu said: "Never strike first—we will absolutely abide by that, despite the pressure our pilots and operators are under."

A fighter jet of Taiwan's Republic of China Air Force takes part in the 37th annual Han Kuang military drills in Pingtung, Taiwan, on September 15, 2021.Taiwan Military News Agency / Ministry of National Defense

In his opening remarks at the top of the session, the minister said the frequent appearances of Chinese warplanes and warships around Taiwan were raising concerns about "gray-zone conflict," intimidating and coercive measures that fall short of war.

Lee Shih-chiang, the Defense Ministry's head strategic planning, said PLA aircraft first crossed into the southwest corner of Taiwan's air defense identification zone in March 2019, a year in which more than 10 such sorties occurred. In 2020, there were 380 flights into the ADIZ. As of October 5 this year, there had been 672 sorties—including 150 in the first five days of the month.

Lee called the activity "pointed military provocations." Taiwan's President Tsai Ing-wen—responding for the first time on Wednesday—accused China of undermining peace and stability in the region and urged Beijing to "exercise restraint."

In illustrating Taiwan's "quiet urgent" need for the special defense budget, Chiu said the Chinese military would have the means to launch a "full-scale" invasion and an effective blockade of Taiwan by 2025. China already has the capacity to launch an attack, Chiu explained. "By 2025, its cost and attrition will be at their lowest."

The proposed special budget, he added, would "quickly elevate Taiwan's combat readiness and national defense capabilities in existing and mature areas such as missiles and ships."

Having received preliminary approval following a 10-hour review, the budget items now head into cross-party deliberations.