The guided missile cruiser Varyag, the flagship vessel of Russia's Pacific Fleet, arrives at Qingdao Port for a joint naval exercise on Monday, April 29, 2019. China and Russia will hold the Joint Sea 2019 naval exercise near Qingdao from until May 4. [Photo: China Plus/Zhang Jin]"

The People's Liberation Army (PLA) Navy Deputy Commander Qiu Yanpeng shakes hands with a Russian navy officer during a welcoming ceremony in Qingdao, Shandong Province, on Monday, April 29, 2019. The Sino-Russia Joint Sea 2019 naval exercise involves two submarines, 13 ships, fixed-wing aircraft, helicopters and marines from both sides. [Photo: China Plus/Zhang Jin]"

Russian navy officers receive flowers from Chinese children at Qingdao Port during a welcoming ceremony for Russian ships at the Sino-Russia Joint Sea 2019 naval exercise on Monday, April 29, 2019. [Photo: China Plus/Zhang Jin]"

The People's Liberation Army (PLA) Navy Deputy Commander Qiu Yanpeng (R3) and Admiral Aleksandr Viktorovich Vitko (L3) of the Russian Navy attend the welcoming ceremony for Russian navy ships in Qingdao, Shandong Province, on Monday, April 29, 2019. The Sino-Russia Joint Sea 2019 naval exercise will focus on "joint defensive activities at sea". [Photo: China Plus/Zhang Jin]"

The large anti-submarine ship Admiral Vinogradov of the Russian navy arrives at Qingdao Port for the Sino-Russia Joint Sea 2019 naval exercise on Monday, April 29, 2019. [Photo: China Plus/Zhang Jin]"

The large anti-submarine ship Admiral Tributs of the Russian navy arrives at Qingdao Port for the Sino-Russia Joint Sea 2019 naval exercise on Monday, April 29, 2019. [Photo: China Plus/Zhang Jin]"