Beijing expressed strong dissatisfaction on Thursday after a naval vessel from the United Kingdom sailed into territorial waters off China's Xisha Islands, with China urging an immediate cessation of such provocative actions.

Reuters reported that HMS Albion, a 22,000-ton amphibious warship, passed near the Xisha Islands on August 31 on its way to Vietnam.

"HMS Albion exercised her rights for freedom of navigation in full compliance with international law and norms," Reuters cited a spokesman for the Royal Navy as saying.

The warship illegally entered territorial waters without permission from the Chinese government, and China's Navy, a branch of the People's Liberation Army, verified and identified the warship in accordance with law and warned it to leave, Foreign Ministry spokeswoman Hua Chunying said at a daily news briefing.

The Xisha Islands are an inherent territory of China, Hua said. "The action taken by the British ship violated Chinese law and relevant international law, and infringed on China's sovereignty," and China strongly protests such moves and has lodged solemn representations, she added.

China urged the UK to immediately stop such provocations to avoid harming overall bilateral relations as well as regional peace and stability, she added.

Also on Thursday, Ministry of National Defense spokesman Ren Guoqiang said that such an action undermines China's sovereignty and security interests and can easily lead to accidents in the air and on the sea.

Ren noted that the situation in the South China Sea is becoming better thanks to the efforts made by China and members of the Association of Southeast Asian Nations.

However, some countries outside the region ignore this positive trend, dispatch planes and ships to stir up trouble in the region and disturb peace and security, he said, adding that the Chinese military will take all necessary measures to resolutely defend national security and sovereignty.