A Chinese foreign ministry spokesperson said on Tuesday that Diaoyu Dao and its affiliated islands are China's inherent territory, and China does not accept the unjustified representation by Japan over the patrol by China Coast Guard (CCG) in its territorial waters.

Spokesperson Mao Ning made the remarks at a daily press briefing, in response to a query about media reports that four CCG vessels entered the waters around the Diaoyu Dao on Nov. 16. Minoru Kihara, Japan's chief cabinet secretary, said the country has lodged stern protests over the patrol via diplomatic channels.

"The patrol by the CCG in China's territorial waters is utterly legitimate and justified," said Mao, adding China has rejected Japan's unreasonable representation right on the spot and raised a counter-representation.

China demands that Japan abide by the four-point agreement reached in 2014 regarding handling and improving ties, respect China's territorial sovereignty, and refrain from disrupting the patrol by CCG or taking any steps that may give rise to the escalation of the situation, Mao added.