Chinese and Russian naval forces on Monday launched joint naval exercise in the southern Russian port city of Novorossiysk. With code-named "Joint Sea 2015-I", it is the fourth one since joint China-Russia sea drills began in 2012.

The drills, scheduled from May 11 to May 21 in the Mediterranean and involving nine surface ships from both navies, are to be staged in four phases, focusing on maritime defense, replenishment and escorting.

Nine ships from two sides are present, including China's Linyi and Weifang missile frigates and the supply ship Weishanhu, which has just concluded anti-piracy patrols off the coast of Somalia.

Experts believe It is the farthest one that the Chinese navy has taken part in outside home waters and is the latest sign of close cooperation between China and Russia.

The 11 day exercise is divided into four phases, said deputy commander of the Chinese navy admiral Du Jingchen, according to the website of China's Ministry of National Defense.

The first two days are the preparation period, followed by the assembly of the two navies in the Mediterranean Sea from May 12 to May 17. Exercises to safeguard maritime safety will be conducted from May 18 to May 21.

"The joint drills are not aimed at any third party and have nothing to do with the political situation in that region," said Geng Yansheng, spokesman for the Chinese Defense Ministry. The drills will deepen friendly and pragmatic cooperation between the two countries, and boost response operation capabilities in the event of security threats at sea.

The exercise involves anti-submarine, air defense, and anti-ship missile simulation exercises to prepare the navies against attacks from the air and sea, according to Zhang Junshe, a research fellow at the Chinese Naval Research Institute.

Deputy Commander of the Russian Navy Alexander Fedotenkov said joint naval exercises are an effective way to fight against maritime threats. China and Russia navies have sound relations and they have had jointly completed difficult tasks through close cooperation many times. He believes both sides will be able to successfully complete the exercise subjects and show good professional skills.

The next year's exercise will be held in China's coastal areas, said Zhang Junshe. China and Russia will organize the drill in turn according to routine.

Navy military expert Li Jie believes the Mediterranean is along the One Road and One Way, China needs to improve offshore delivery, supply capacity and emergency crisis management capabilities to ensure waterway safety and protect the national interests and overseas nationals.