Q: According to media reports, Japan’s Maritime Safety Agency stationed for the first time PLH (patrol vessels large with helicopter) in the waters of Diaoyu Islands, saying that the action was aimed to defend against "invasion" from Chinese marine survey ships. How do you comment on this?

A: The Diaoyu Island and its adjacent islets have been China’s inalienable territory since ancient times. China has undisputable sovereign rights over them. Any action by the Japanese side to strengthen actual control over the islands constitutes an infringement upon China’s territorial sovereignty, which is illegal and invalid, and should be stopped immediately.