The Chinese ambassador to Japan said he told Japan's foreign minister that the islands in the East China Sea, claimed by both countries, were an integral part of China's territory and that the two nations' dispute should be resolved through diplomacy and dialogue.

"I told him that the Diaoyu (islands) are an integral part of Chinese territory and that it is natural that Chinese ships conduct activity in the waters in question," Cheng Yonghua told reporters after meeting with Foreign Minister Fumio Kishida on Tuesday.

Tension between the two nations has risen as Japan confirmed an increasing number of Chinese government ships sailing near the disputed islets called Senkaku in Japan and Diaoyu in China over the last few days.