BEIJING - A foreign ministry spokesman said Friday that China is "strongly dissatisfied" with Japan over the Diaoyu Islands issue.

The country does not accept a representation lodged by Japan over the issue, spokesman Liu Weimin said at a regular press briefing.

Japanese vessels interfered with Chinese vessels' official patrol of waters off the Diaoyu Islands, Liu said, adding that China was "strongly dissatisfied" about the incident.

He stressed that Chinese fishery administration vessels entered the waters to conduct routine patrol.

Diaoyu Island and its affiliated islands have been China's inherent territory since ancient times, the spokesman said.