Full coverage: The South China Sea Issue

China and Russia have begun a high-level navy drill today in the South China Sea, off Guangdong province. The Chinese military says it's aimed at enhancing the ability to counter common security threats.

The Russian fleet docks near Zhanjiang, Guangdong province, Monday morning. And "Joint Sea 2016" begins.

Officers and soldiers of Chinese Navy hold a welcome ceremony as a Russian fleet arrive at a port in Zhanjiang, south China's Guangdong Province, Sept. 12, 2016. A Russian fleet arrived in Zhanjiang on Monday, with Chinese naval forces gathering for a joint drill. The "Joint Sea 2016" drill will go ahead between September 12 and 19 in the South China Sea, off Guangdong. (Xinhua/Zha Chunming)

The annual exercise, now in its sixth year, involves the best naval forces from both sides.

This year, 10 ships from the Chinese navy, some of them from the Nanhai Fleet, and 5 from Russia are taking part in the week-long exercise.

In addition, Chinese navy is deploying 11 aircraft, eight helicopters, and amphibious armored equipment.

The focus is expected to be on anti-submarine warfare, and landing operations on islands and reefs.

"Compared with previous drills, this drill has improved on organization, command issuance, deployment and other areas. It will also highlight digitalized and standardized use of forces in combat," said Liang Yang, spokesperson of Chinese Navy.

The joint drill is of the largest scale in the China-Russia framework.

This year also marks the 20th anniversary of the two navies' strategic cooperation.