Military observers believe the first joint naval drill of Chinese and Russian naval forces in the Mediterranean Sea suggests the two countries' determination to further strengthen their military ties amid potential international conflicts.

Analysts also see the rare Mediterranean drill in mid-May as a sign that China is fully capable and prepared to protect its commercial interests where countries in the region, such as Libya and Syria, have witnessed escalating tensions.

Since China's Defense Ministry made the announcement on April 30, the exercise has drawn intense media attention over its political and military implications. 

"It is the fourth time the two countries have conducted a joint naval drill. Both China and Russia have conducted naval activities in the region. The joint drill is their latest move in strengthening naval cooperation," Zhang Junshe, a research fellow at the Chinese Naval Research Institute, told the Global Times.

A total of nine ships from the two countries will participate in the drill, including vessels China now has on anti-piracy patrols in waters off Somalia, Chinese defense ministry spokesman Geng Yansheng said at a monthly news briefing.

Geng said the aim is to deepen both countries' cooperation and to increase their navies' ability to jointly deal with maritime security threats.

"We have to stress that these exercises are not aimed at any third party and have nothing to do with the regional situation," he said.

The May exercises will focus on navigation safety, at-sea replenishment, escort missions and live-fire drills, said Geng, who gave no further details.

The two countries held their first naval drill in Pacific waters in 2012. 

Li Jie, a Beijing-based naval expert, believes that the joint naval drill in May will also help to safeguard China's regional commercial interests.

"The Mediterranean Sea is an important trade route linking China with Europe. It is also one of the key regions of China's 'One Belt, One Road' initiative. China's regional naval presence will ensure its maritime safety," Li told the Global Times.

Russia has a regular naval presence in the Black Sea which discharges into the Mediterranean Sea. China's navy began expanding its reach toward the Mediterranean in 2008, when it first sent ships to join in anti-piracy patrols.

In 2011, China evacuated 35,000 citizens from Libya during its civil war, followed by another effort in 2013 when it joined Russia in sending warships to Syria to peacefully monitor developments in the region through waterways close to the Mediterranean Sea.

In April, China dispatched three navy ships from its anti-piracy patrols to evacuate Chinese citizens and other foreign nationals from fighting in Yemen.

The US has maintained a naval presence in the Mediterranean since the early 19th century, and has in recent years considered increasing its military presence in the region.

Su Hao, director of the Asia-Pacific Research Center of the China Foreign Affairs University, told the Global Times that since Chinese President Xi Jinping is expected to visit Moscow from Friday to Sunday to attend a parade celebrating the end of World War II, it is important for the two major anti-fascist countries to show unity and reaffirm their military ties.

Russian President Vladimir Putin will also attend China's military parade in September to commemorate the 70th anniversary of the victory in the Chinese People's War of Resistance against Japanese Aggression as well as in the World Anti-Fascist War, China News Service reported on March 20.

Meanwhile, Estonia kicked off its largest military drill on Monday, involving some 13,000 servicemen from NATO nations and their allies, including the US, the UK and Germany, with analysts believing that the drill is targeting Russia.

"China and Russia have their own strategic interests in the Mediterranean Sea. Russia's intended military presence in Europe has been restricted by NATO. Its expanding reach into the Mediterranean will in return create pressure for the US and NATO and will help Russia keep its hold of Crimea," Su said.

Russia has been subjected to economic sanctions over its position in Ukraine which Washington said is threatening its NATO allies in Eastern Europe.

Du Wenlong, a senior researcher at the People's Liberation Army's Academy of Military Science, said the US is likely to conduct air and sea reconnaissance operations during the drill, taking advantage of its vast military presence in the region to gather intelligence on Sino-Russia military cooperation, reported ifeng.com.