Ukraine has taken American Abrams M1A1 battle tanks off the frontline, partly because of Russian drone tactics, Pentagon officials have said. The US agreed to send 31 Abrams to Ukraine in January 2023. Five have been lost to Russian attacks.

The proliferation of drones means “there isn’t open ground that you can just drive across without fear of detection”, a senior defence official said on Thursday. “Now, there is a way to do it,” he said. “We’ll work with our Ukrainian partners, and other partners on the ground, to help them think through how they might use that, in that kind of changed environment now, where everything is seen immediately.”

The Ukrainians have not adopted tactics that could have made the tanks more effective, one of the US defence officials said, such as in combined-arms warfare, training for which was provided by the US in Germany. Russian forces have sustained heavy losses of their own tanks and armoured equipment due to highly effective surveillance and attacks by Ukrainian drone warfare units.