By Guy Faulconbridge and Lidia Kelly
MOSCOW (Reuters) -Russia's navy began planned exercises involving most of its fleet in the Arctic and Pacific oceans as well and the Baltic and Caspian seas, the defence ministry said on Tuesday.
Russia is considered by most military analysts to have the world's third most powerful navy after those of the United States and China, and Russia has a significant ballistic-missile nuclear submarine fleet.
The Russian drills, which include 20,000 personnel and 300 ships, will test the readiness and capabilities of the navy at all levels, the ministry said.
The drills will include over 300 combat exercises including practicing the use of anti-aircraft missiles, artillery, anti-submarine weapons and "passive interference, it added.
"Units and formations of the Russian Navy have begun conducting planned exercises in the operational zones of the Northern, Pacific and Baltic Fleets, as well as in the area of responsibility of the Caspian Flotilla," the ministry said.
"The main purpose of the exercises is to check the actions of the military authorities of the navy at all levels, as well as the readiness of the crews of ships, units of naval aviation and coastal troops of the Russian navy to perform tasks."
About 300 surface ships and boats, submarines and support vessels, some 50 aircraft and more than 200 units of military and special equipment will be involved in the combat training, the ministry said.
Since President Vladimir Putin sent thousands of troops into Ukraine in February 2022, the Russia's Black Sea fleet - the only Russian fleet formation not taking part in the drills - has struggled to adapt to dynamic modern drone warfare and the chief of the navy was replaced earlier this year.
At celebrations of Russian navy day on Sunday, Putin warned the United States that if Washington deployed longer range missiles in Germany then Russia would station similar missiles in striking distance of the West.
Since launching an invasion on Ukraine in February 2022, Russia has conducted numerous military exercises on its own or with other countries, including China or South Africa.
In the past two months, Russia has also conducted a series of mobile nuclear missile launcher drills and tactical nuclear weapons deployment exercises. It has also increased military training with Belarus, which borders both Russia and Ukraine, conducting a series of comprehensive drills.
(Writing by Lidia Kelly in Melbourne and Guy Faulconbridge in Moscow; Editing by Christopher Cushing and Michael Perry and Miral Fahmy)