A Chinese navy helicopter takes off from China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

Chinese Navy soldiers work on a helicopter before sending it into hangar on China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

Chinese and Russian vessels gather at designated sea area during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

A commander directs a navy helicopter to take off from China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

A Chinese navy helicopter takes off from China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

China's Harbin missile destroyer fires at a target during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

Li Yigang, captain of China's Zhengzhou missile destroyer, makes the order to fire a target during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

A Chinese navy helicopter prepares to take off from China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

Chinese and Russian vessels gather at designated sea area during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

China's Ningbo missile destroyer fires anti-submarine missile during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

 A navy helicopter returns to China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

China's Ningbo missile destroyer (L) and Harbin missile destroyer (R) gather at designated sea area during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

A navy helicopter returns to China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

Chinese navy soldiers work on a helicopter before sending it into hangar on China's Zhengzhou missile destroyer during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)

 

Chinese and Russian vessels gather at designated sea area during the China-Russia joint naval drill on East China Sea, May 24, 2014. The three-day drill "Joint Sea-2014" ended successfully on Saturday. The Chinese and Russian navies staged exercises, including joint escort drill, joint aircraft identification exercise and air defense and maritime assault drills. (Xinhua/Zha Chunming)