Russia's constant military expansion has led it to surpass the United States in terms of manufacturining new war planes. News of Russia's increased military activity to protect its interests has added to the tension in Europe on top of the sanctions imposed by the West over its meddling in Ukraine.

According to the Russian United Aircraft Corporation, Russia has built more combat aircraft than the U.S. in 2014. Vladislav Goncharenko, deputy head of the military aviation programme department of UAC, said in an interview with radio station Ekho Moskvy, confirmed the information. He said UAC delivered 68 planes and 100 others including 95 attack planes for the use of the Russian Air Force in 2014.

The deputy head said the UAC subsidiaries are currently modernising the military's existing aircraft and the developing new weapons systems. The number of new aircraft being delivered for use in the frontline of the Russian Air Force may be a clear indication that the government is intensifying efforts to increase the country's military power, The Aviationist reported.

Meanwhile, the recent announcement of the successful testing of the U.S. Navy's GhostSwimmer underwater drone has prompted Russia to respond. According to the Washington Times, Russia is also close to completing its unmanned submarines. The U.S. Navy Pacific Command revealed the successful testing phase last week. In a statement released by the Pacific Command, Michael Rufo, Boston Engineering's Advanced Systems Group director, said GhostSwimmer will increase the U.S. Navy's success rate in missions while keeping more sailors and divers safe.

Following the announcement, Russia Today headlined a story that Russia's fifth-generation submarines will be equipped with underwater drones. Despite announcing their own development of underwater drones, the Russians did not give away much about its own technology. However, the U.S. Navy said its own 5-foot drones weigh 100 pounds and have the ability to mimic aquatic life. Rufo reported that the U.S. drones can swim like a fish by moving its tail back and forth.

Navy Warfare Development Command concepts and innovation department head Capt Jim Loper revealed in a report by that the underwater drones can remain in water for days or weeks on battery. The unmanned sea vehicle will be equipped with a sensor so it can match marine life movements.

Russia has been accused of arming separatists in Ukraine by the West, but Moscow has repeatedly denied any involvement. The country is currently on the brink of an economic crisis as oil prices continue to drop, along with the local currency.