Half of Russia’s main battle tanks have likely been destroyed or captured, a senior US defence official said.
Celeste Wallander, the assistant secretary of defence for international security affairs, said on Friday that Moscow had “probably lost half of its main battle tank stock in combat and through Ukrainian capture”.
The losses come as Ukraine is set to receive an influx of heavy Western tanks from its allies.
Britain has said its Challenger 2 tanks will be deployed in Ukraine in March, while Germany and its allies aim to deliver a battalion of Leopard 2 tanks by April.
The United States has also promised a battalion – or 31 – of its M1 Abrams tanks.
Meanwhile, Russian missiles hit power facilities across Ukraine on Friday, in what is believed to be the start of a major new Russian offensive.