WASHINGTON (AA) - Russia has suffered more than 100,000 combat casualties since December, the White House said Monday ahead of an expected Ukrainian counteroffensive to take back territories occupied by the Kremlin.

The casualty toll includes over 20,000 deaths and 80,000 injuries, National Security Council spokesperson John Kirby told reporters during a press briefing. About half of all of the Russian dead were mercenaries affiliated with the Wagner Group, a Russian private military company closely associated with President Vladimir Putin, he said.

The bulk of the casualties have occurred in or near Bakhmut, a city in eastern Ukraine that has been the scene of fierce fighting for months as Russian forces attempt to encircle and seize it.

"It's really stunning, these numbers. The bottom line is that Russia's attempt at an offensive has backfired. After months of fighting and extraordinary losses, Russia continues to be focused on a single Ukrainian city with limited strategic value," said Kirby.

"Ukraine's armed forces are defending their territory bravely and effectively and making Russia expend enormous resources for marginal gains," he added.

On April 24, the head of the Wagner Group said his forces in the frontline city of Bakhmut are “successfully grinding” with the Ukrainian army.

“Our task (in Bakhmut) is to grind the Ukrainian army, not to give them the opportunity to gather in a counter-offensive. We are doing this more than successfully,” Yevgeny Prigozhin said in a statement on Telegram.

Moscow on Sunday claimed its forces took control of four more urban quarters in Bakhmut. The Russian Defense Ministry said units of the Airborne Forces pinned down Ukrainian forces in the northern and southern outskirts of the city.

Kirby said the majority of Wagner Group's dead are convicts recruited into the paramilitary with the promise of an erased prison sentence, but are instead being used "to throw human flesh at this fight."

Michael Hernandez/AA