US intelligence believes 'slaughter-fest' fighting in Ukraine has cost Russia 100,000 dead and wounded in only a matter of months, White House reveals

• Russia has suffered 100,000 casualties since December, a top White House official said, citing US intelligence.
• John Kirby revealed that 20,000 Russian troops have been killed fighting in Ukraine in that time.

Russian forces have suffered over 100,000 casualties during intense and brutal fighting in Ukraine over the past five months, a top White House official revealed on Monday, highlighting a notable increase in Moscow's troop losses.

Ukrainian troops have fought the Russians along a largely static front line across eastern and parts of southern Ukraine for months. During this time, hostilities have been largely centered around the war-torn city of Bakhmut in the Donetsk region, and the fight for this town has become the longest and bloodiest battle since Russian troops invaded Ukraine last year.

National Security Council spokesperson John Kirby told reporters in a briefing that over 20,000 Russian soldiers have been killed and another 80,000 have been wounded in fighting since December. Kirby cited unspecified but declassified US intelligence in providing the assessment, the Associated Press reported.

He further added that around half of Russia's dead are mercenaries from the Wagner Group, a notorious paramilitary organization with close ties to the Kremlin that has been fighting alongside Russia's regular military.

The staggering figure is yet another indication of how costly the conflict has been for Moscow's military. Chairman of the Joint Chiefs of Staff Gen. Mark Milley said in late March that the battle for Bakhmut had turned into a "slaughter-fest" for Russian forces, who had issues with logistics, troop training, and operational tactics.

"They are getting hammered in the vicinity of Bakhmut, and the Ukrainians are fighting very, very well," Milley said at the time. Russian forces have managed to put pressure on the Ukrainian defenders, but despite Moscow's continuous and unrelenting efforts to capture the city — which experts argue has limited strategic importance — its troops have been unable to do so as of the beginning of May.

Kirby's comments on Monday mark the latest Western estimate of Russian casualties, which appear to have skyrocketed in recent months as Moscow's troops facing a stiff Ukrainian defense have struggled to make significant territorial gains.

In November 2022, after the first eight months of war, Milley estimated that over 100,000 Russian soldiers had been killed or wounded since the initial full-scale invasion. In January 2023, the top general went on to say that Russia had suffered "significantly well over" 100,000 casualties.

Britain's defense ministry shared in a mid-February intelligence update that Russian-linked forces — which includes Wagner — may have suffered as many as 200,000 casualties, including up to 60,000 killed. That same month, the Center for Strategic & International Studies estimated that up to 70,000 Russians may have died in combat, which is more Russian dead in a single conflict than all Russian wars since World War II.

Recently leaked US intelligence documents reviewed by Insider suggested that Russia had endured up to 223,000 casualties, including 43,000 soldiers killed in fighting. It's unclear when, exactly, that data was compiled, although similar documents obtained by Insider were from late February or early March.

Monday's casualty figure — 100,000 — matches what Milley reported in November of last year, meaning it took Ukraine only five months to double the number of casualties that it inflicted on Russian forces during the first eight months of the war. It is unclear what Ukraine's casualty figures look like, though the leaked military intelligence documents indicated that Ukraine could have as many as 131,000 casualties with up to 17,500 killed in action.

Meanwhile, fighting in Bakhmut shows no signs of slowing down. Ukraine's General Staff of the Armed Forces wrote in a Monday Facebook post that Russia continues to carry out offensive actions around Bakhmut, but noted that its attacks are being repelled by the Ukrainian troops.