Russian aircraft carrier Admiral Kuznetsov sails in the Barents Sea in 2004. (Xinhua/AP photo)

MOSCOW, April 12 (Xinhua) -- Russia's only aircraft carrier, Admiral Kuznetsov, will return to the navy in 2021 after its upgrading is completed in 2020, Deputy Defense Minister Yuri Borisov said Thursday.

The vessel will be completely refurbished at the 35th Ship Repairing Yard in Murmansk in northwest Russia, Borisov said.

In June 2017, Viktor Bursuk, deputy navy commander in charge of procurement, said Russia would start repairing Admiral Kuznetsov in 2018 and arm it with new equipment.

Russia also plans to construct a new aircraft carrier and various engineering centers are working to determine the design of this ship, Bursuk said then, giving no more details.

The 305-meter-long Admiral Kuznetsov with a displacement of 59,000 tons was launched in 1985 and entered service in 1990.

The warship carried out its first-ever combat mission in 2016 in the Mediterranean fighting Islamic State terrorists in Syria.

Its aircraft carried out 420 sorties in two months, but two jets fell off the deck after the arresting wires snapped. The vessel returned to its home base in February 2017 after the deployment was completed.