May 22, 2015 7:01 AM

China and Russia conducted joint naval exercises this week in the Mediterranean Sea — a sign, some security experts say, that the two countries are stepping up defense cooperation to offset U.S. military primacy.

The Russian Defense Ministry said a total of 10 warships from the Russian Navy and China’s People's Liberation Army Navy took part in the week-long exercises. The Chinese Defense Ministry said the joint exercises focused on navigation safety, at-sea replenishment, escort missions and live fire exercises.

15:41 May 12, 2015 Interfax

Russian and Chinese naval ships are expected to sail out of the Novorossiysk port and head to the Mediterranean Sea to hold their Joint Sea-2015 maneuvers, on Tuesday, the Russian Defense Ministry has reported.

"The active phase of the exercises will take place in a certain district of the Mediterranean Sea from May 17 to May 21," the ministry's spokesman for the Navy Captain 1st Rank Igor Dygalo told Interfax-AVN on Tuesday.

The unit of the Russian Navy and the People's Liberation Army Navy of China includes China's Linyi and the Weifang frigates and the Russian Black Sea Fleet's Samum amphibious ship, he said. They are expected to cross the Black Sea, sail through the Bosporus and the Dardanelles and catch up with other ships participating in the maneuvers in the eastern part of the Mediterranean Sea.

Antonov also said he was concerned about stability in the region, naming the US as the main destabilizing factor. He said that Washington's policies have been aimed against Russia and China: "We are concerned by US policies in the region, especially since every day it becomes increasingly focused on a systemic containment of Russia and China."