The Chinese military protested on Thursday after a British Royal Navy warship sailed close to Chinese islands in the South China Sea on Aug 31, calling the act a provocation and an infringement on Chinese sovereignty, the ministry spokesman said.

The HMS Albion, a 22,000-metric ton amphibious warship, illegally entered the waters near China's Xisha Islands without permission, Senior Colonel Ren Guoqiang, a spokesman of the Ministry of National Defense, said in an online statement Thursday afternoon.

In response, the Chinese military has dispatched ships and planes to identify and warn the ship to leave in accordance with laws and regulations, he said.

"The Xisha Islands have been a part of China's territory," he said, adding China had published the baseline of the territorial sea surrounding the islands in May 1996.

The British navy entering Chinese territorial waters is a provocative move, Ren said. It violates Chinese and relevant international laws, undermines China's sovereignty and security interests, and can easily lead to accidents both in the air and on the sea, he added.

China strongly protests such acts and has launched a solemn complaint to the British side, he said.

The situation in the South China Sea is becoming better thanks to the efforts by China and ASEAN countries. However, some countries outside of the region ignore this positive trend, and dispatch planes and ships to stir trouble in the region and disturb regional peace and security, he said.

This goes against the effort and common aspirations of countries in the region, he said. The Chinese military will take all necessary measures to resolutely defend national security and sovereignty, as well as regional peace and security.