Spokesperson Wu Qian of the Ministry of National Defense made a speech on Tuesday on the issue of the USS Decatur entering an adjacent area to islands in the South China Sea without permission on Sept 30, 2018. A Chinese navel ship reacted immediately to identify the US ship and warned it off, resolving the situation.

Wu said China has indisputable sovereignty over the South China Sea islands and their adjacent waters. However, the US sent vessels to enter the China South Sea without permission, threatening China's sovereignty and security and harming the two countries' and militaries' relationship, as well as the region's peace and stability.

The Chinese military will always fulfill their duty and continue to protect China's sovereignty and security, as well as regional peace and stability using every necessary measure, Wu said.