Russia’s winter push in Ukraine may have made little progress and at a “stunning” cost.

The Kremlin’s forces have suffered more than 100,000 killed or wounded fighters since December alone, the United States now estimates — outlining Moscow's massive losses as its military leaders scramble to recruit more men and prepare for an impending counteroffensive.

The figure, if accurate, could spell trouble ahead for President Vladimir Putin: He faces a second year at war with the land he has seized in Kyiv's sights and his military's struggles forcing the Kremlin to balance battlefield necessity with domestic pressures.

The casualty figure includes around 20,000 Russians who have been killed in about six months, National Security Council spokesman John Kirby told reporters Monday, citing newly declassified American intelligence that the Kremlin swiftly rejected.

For comparison, around 4,500 American troops have been killed since the invasion of Iraq a decade ago.

"It's really stunning, these numbers," Kirby said.

Half of those killed were from the Wagner mercenary group, the majority of whom were ex-convicts “thrown into combat” in Bakhmut, Kirby said, who lacked “sufficient combat training, combat leadership or any sense of organizational command and control.”

The eastern mining city has turned into something of a modern day Stalingrad and became the focus of a Russian winter offensive that was fueled by the call-up of hundreds of thousands of military reservists but that has failed to make substantive progress.

Both sides have suffered heavy losses in and around the city, with their armies bogged down in a brutal battle of attrition that has seen Russian troops make steady incremental gains but fall short of what would be a symbolic victory.

Some Western analysts criticized Kyiv’s decision to contest the city, arguing it should have pulled back weeks ago in a move that would have allowed Russia a short-term win but preserved Ukrainian soldiers for its own looming counteroffensive.

But the figures released by Kirby will give weight to the Ukrainian counterargument, that fighting for Bakhmut would allow them to kill lots of Russians, while also preventing them from being deployed elsewhere.

Russia’s attempted winter offensive through the city has “stalled and failed” and “backfired,” Kirby said. And Russia “has been unable to seize any real strategically significant territory” after “months of fighting and extraordinary losses," he added.