Japan slammed on Tuesday what it called the first confirmed incursion by a Chinese military aircraft into its airspace as a "serious violation" of its sovereignty.
"The violation of our airspace by Chinese military aircraft is not only a serious violation of our sovereignty but also a threat to our security and is totally unacceptable," Japan's chief government spokesman Yoshimasa Hayashi told reporters.
Meanwhile, Japan's Defense Minister Minoru Kihara slammed the breach of Japan's airspace by the Chinese military plane, calling it a "totally unacceptable".
Japans military said on Monday that a Chinese Y-9 reconnaissance plane had been detected circling above the Danjo Islands off the southwestern coast of Japans main southern island of Kyushu for two minutes, and fighter jets had been scrambled to warn the Chinese plane to leave the airspace.
Japan's Ministry of Foreign Affairs later said that it had summoned acting Chinese Ambassador Shi Yong to lodge a strong protest over the airspace violation, and demand China take preventive steps to avoid such incident