A C-40A Clipper transport, a military version of the Boeing 737 passenger aircraft, on June 9 made an unusual flight when taking off from Okinawa, Japan to Southeast Asia.

The transporter’s unusual journey is seen as a sign of growing US support for Taiwan, as mainland China has recently increased military exercises near the island

However, it also sparked an angry response from China.

`The rare flight of a US transport plane shows growing cooperation between the US military and separatists in Taiwan. Mainland Chinese jet fighters sortied and approached to send them a warning

Flight path of the US Navy’s C-40A transport from Okinawa to Taiwan, June 9.

Beijing-based military expert Song Zhongping said that the PLA’s Su-30 fighter entering Taiwan’s ADIZ `is most likely in response to the aggressive actions of US military aircraft`.

Song also said that the Su-30 fighter’s invasion of Taiwan’s ADIZ was a deliberate move by the PLA.

Taiwan recently accused mainland China of stepping up military activities in the area around the island, seeing it as a deliberate action to intimidate Taiwanese authorities after leader Tsai Ing-wen took office in office.

However, Beijing insists these military exercises are nothing unusual and that they `take place on Chinese territory.`

Su-30 fighter of the Chinese navy during a training exercise in February. Photo: PLA.

PLA spokesman Wu Qian in May stated, `Taiwan is an inalienable part and an internal matter of China. China does not accept any acts of interference by other countries.`

`The PLA has a firm will, enough confidence and ability to prevent all separatist attempts by foreign forces. The PLA will take all necessary measures to protect national sovereignty and territorial integrity