Advanced tanks donated by the US have been pulled from the front lines in Ukraine to avoid attacks by Russian drones.

Abrams M1A1 battle tanks, which cost about $10 million each, are no longer safe from the growing threat of unmanned aerial vehicles that have changed the face of the war.

Five of the 31 tanks have already been lost to Russian attacks, US officials said as they admitted they had been forced to review tactics.

The proliferation of drones on the Ukrainian battlefield means “there isn’t open ground that you can just drive across without fear of detection,” a senior defence official said.

The tanks have been moved from the front lines while the US works with Ukrainians to reset tactics, said Joint Chiefs of Staff Vice Chairman Adm Christopher Grady.

“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.”

Advanced and rudimentary drone warfare has revolutionised front-line conflict, forcing both sides to adapt. But the setback with Abrams comes as outgunned Ukraine is on the back foot, with Russia seizing a number of towns and villages in a series of successful advances this year.

Follow the latest updates below