US estimates estimate that more than 20,000 Russian troops have been killed in Ukraine since December.
According to recently disclosed intelligence, an additional 80,000 people have been injured, according to National Security Council spokesman John Kirby.
The Wagner mercenary company, which has been targeting the eastern Bakhmut city, is responsible for half of the deaths.
Russia has been waging an attritional campaign against the little city since last year.
Although Moscow controls the majority of Bakhmut, Ukrainian troops still control a small portion of the city to the west. For both sides, the fierce battle has taken on enormous symbolic significance.
Ukrainian leaders have also stated that they intend to kill as many Russian troops as possible in order to deplete Russia’s reserves.
“Russia’s attempt to launch an offensive in the Donbas [region] largely through Bakhmut has failed,” Mr Kirby told reporters. “Russia has failed to seize any truly strategic or significant territory.”
“We estimate that Russia has suffered over 100,000 casualties, including more than 20,000 killed in action,” he continued.
According to US estimates, the toll in Bakhmut accounts for losses since the beginning of December.
“The bottom line is that Russia’s attempted offensive has backfired after months of fighting and extraordinary losses,” said Mr Kirby.
He stated that he was not providing casualty figures for Ukrainians since “they are the victims here.” The attacker is Russia.”
The takeover of the city would put Russia one step closer to gaining control of the entire Donetsk region, one of four regions in eastern and southern Ukraine annexed by Russia last September following referendums generally regarded as a fraud outside Russia.
According to analysts, Bakhmut has limited strategic relevance, but it has become a focal point for Russian commanders who have failed to provide favourable news to the Kremlin.
The Wagner mercenary outfit, which frequently employs prisoners and has grown known for its often harsh tactics, has taken central stage in Russia’s assault on Bakhmut.
Yevgeny Prigozhin, its leader, has placed his reputation and that of his private army on taking the city.
However, he recently threatened to withdraw his troops from Bakhmut.
In a rare in-depth interview with a popular Russian war blogger, he threatened to withdraw Wagner warriors if the Russian defence ministry did not provide them with much-needed ammo.
He warned that Wagner fighters may be redeployed to Mali.
Throughout the war, he has frequently clashed with Russia’s defence ministry, accusing officials of failing to provide his fighters with adequate support.
Mr. Prigozhin also urged Russia’s media and military leadership to “stop lying to the Russian people” in advance of a predicted Ukrainian spring attack.
“We must stop lying to the Russian people and telling them everything is fine,” he stated.
He lauded Ukraine’s force for its “good, correct military operations” and command.