Taipei: As Nancy Pelosi, the speaker of the US House, started her contentious visit to the self-governing island that Beijing claims as its own, more than 20 Chinese military aircraft flew into Taiwan's air defence zone, officials in Taipei said. The air defense identification zone, or ADIZ, was breached by 21 PLA aircraft on August 2, 2022, defence minister said in a tweet. The ADIZ is larger than Taiwan's territorial airspace, overlapping with areas of China's own air defence identification zone and even extending into parts of the mainland. Tuesday night, Pelosi arrived in Taiwan, defying a series of dire warnings and threats from China that have raised tensions between the two heavyweights of the world. Pelosiis the highest-profile elected US official to visit Taiwan in 25 years and is second in line to the presidency. Beijing has made it clear that it views her presence as a serious provocation, which has put the region on edge. The 82-year-old lawmaker, who flew on a US military aircraft welcomed at Taipei's Songshan Airport by foreign minister Joseph Wu, as shown on live broadcasts. She said in a statement upon her arrival that her visit "in no way undermines" US policy towards Taiwan and Beijing and "honours America's unshakable commitment to support Taiwan's vibrant democracy." Taiwan said that Washington's backing was "rock strong" as evidenced by the visit. Pelosi is currently on a tour of Asia, and while neither she nor her staff have confirmed a trip to Taipei, many US and Taiwanese media sites have reported that one is planned, setting off days of building resentment in Beijing. In response to the visit, China's military announced it would "launch a series of targeted military strikes" and was on "high alert." It quickly made plans public for a series of military drills to start on Wednesday in the waters surrounding the island, including "long-range live ammo fire" in the Taiwan Strait. If Pelosi visits Taiwan it can be Beijing's response China threatens the US once more over Pelosi's potential trip to Taiwan and realigns aircraft carriers Nancy Pelosi departs for an Asia tour, but Taiwan is not mentioned on the itinerary