BEIJING - A Chinese Foreign Ministry spokesman said ?Wednesday that China is on high alert for Japan escalating tensions over the Diaoyu Islands.

Spokesman Hong Lei made the remarks in response to media reports saying Japanese Defense Minister Itsunori Onodera on Tuesday expressed a stance of handling Chinese jets entering airspace over the Diaoyu Islands with international standards.

"China has taken note of relevant reports. The patrol conducted by China's public service ships and planes in waters and airspace of the islands is a normal performance of duty to exercise jurisdiction," Hong said.

He also reiterated China's opposition to Japanese planes and vessels entering the waters and airspace of the Diaoyu Islands.

Relations between Japan and China have soured since the Japanese government said it would "purchase" part of the Diaoyu Islands in the East China Sea in 2012. China insists that the islands are part of its inherent territory.

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