BEIJING - A spokesman for China's Foreign Ministry on Tuesday expressed strong dissatisfaction over Vietnamese fighters' recent patrolling and reconnaissance on Nansha Islands in the South China Sea.

Speaking at a regular press briefing in response to a journalist's question on the subject, Hong Lei said, "China has indisputable sovereignty over the Nansha Islands and their adjacent waters. Vietnam's recent action is a serious violation of China's sovereignty."

He said China urges Vietnam to strictly abide by the Declaration on the Conduct of Parties in the South China Sea, avoid actions escalating or complicating the situation, and make efforts to safeguard regional peace and stability.