The White House on Monday estimated that Russia's military has suffered 100,000 casualties in the last five months in fighting against Ukraine in the Bakhmut region.
White House national security spokesperson John Kirby told reporters the figure, based on US intelligence estimates, included more than 20,000 dead, half of them from the Wagner mercenary group, which includes convicts released from prison to join the fighting.
The Bakhmut offensive failed
"Russia's attempt at an offensive in the Donbass largely through Bakhmut has failed," Kirby said. "Russia has been unable to seize any real strategic and significant territory."
He said the Russians have made some incremental gains in Bakhmut but that this has come at a "terrible, terrible cost" and that Ukraine's defenses in the region remain strong.
"Russia has exhausted its military stockpiles and its armed forces and since December alone, we estimate that Russia has suffered more than 100,000 casualties, including over 20,000 killed in action, nearly half of whom were Wagner soldiers," he said.
"It's really stunning, these numbers," Kirby added, saying the total is three times the number of American casualties in the Guadalcanal campaign in World War Two.
Kirby said another US weapons package for Ukraine would be announced soon.
Russia's response to the estimates
The Kremlin on Tuesday rejected a US assessment of Russian military casualties in Ukraine as having been "plucked from thin air" and said that Washington had no way of obtaining the correct data.
Russia last publicly revealed its own tally of losses in the campaign in September, when Defence Minister Sergei Shoigu said 5,937 Russian soldiers had been killed in the conflict.