Russia has lost around 15,000 troops since the beginning of the war in Ukraine, according to the UK government.
Defence secretary Ben Wallace said Moscow had also thousands of armoured vehicles, tanks, helicopters and fighter jets in the conflict.
The shocking death toll is further evidence of how badly the war is going for Vladimir Putin and of the fierce resistance being put up by the Ukrainian forces.
In a statement to MPs, Wallace said: “It is our assessment that approximately 15,000 Russian personnel have been killed during their offensive.
“Alongside the death toll are the equipment losses and in total a number of sources suggest that to date over 2,000 armoured vehicles have been destroyed or captured.
“This includes at least 530 tanks, 530 armoured personnel carriers and 560 infantry fighting vehicles.
“Russia has also lost over 60 helicopters and fighter jets.
“The offensive that was supposed to take a maximum of a week has now taken weeks.”
The Ministry of Defence this morning claimed Vladimir Putin was hiding the true scale of troop losses from the Russian people.
Officials said Russia had proposed that compensation payments for the families of dead soldiers would be overseen by “military rather than civilian officials”.
The MoD added: “This likely reflects a desire to hide the true scale of Russia’s losses from the domestic population.”
Wallace said Russia has so far “failed in nearly every one of its objectives”, adding: “In recognition of this failure the Russian high command has regrouped, reinforced and changed focus to securing Donetsk and Luhansk oblast.”
He added: “At the start of this conflict Russia had committed over 120 battalion tactical groups, approximately 65 per cent of its entire ground combat strength.
“As of now we assess around over 25 per cent of these have been rendered not combat effective.
“Ukraine is an inspiration to us all. Their brave people have never stopped fighting for their lands. They have endured indiscriminate bombardment, war crimes and overwhelming military aggression but they have stood firm, galvanised the international community and beaten back the army of Russia in the north and the north east.
“We anticipate this next phase of the invasion will be an attempt by Russia to occupy further the Donbas and connect via Mariupol the Crimea so it’s urgent that we in the international community ensure Ukraine gets the aid and weapons it so much needs.”