BERLIN — Even as President Vladimir Putin hails Russia’s advances on the battlefield, four years into his invasion of Ukraine, his force has suffered perhaps the worst losses any major power has seen in a conflict since World War II.

There is little sign that the conflict is getting any less deadly, as Ukraine looks to harness new battlefield technology to raise the cost of Russia’s gains. Estimates suggest that the death toll for the entire war among Russian and Ukrainian fighters could rise beyond 500,000 this year, with deaths adding up particularly on the advancing Russian side.

Heavily Guarded Secret

The number of soldiers killed in the war remains a heavily guarded secret on both sides, as Moscow and Kyiv aim to avoid projecting weakness.

But some estimates indicate that Ukraine has lost more soldiers as a proportion of its wartime population than Russia has, even if Russian losses have been far larger overall. Estimates put the number of Russian troops killed at more than five times the losses that the U.S. military suffered during the Vietnam War.

Journalists from the independent Russian news outlet Mediazona and the BBC Russian Service published new results Tuesday of their effort, dating to the early months of the invasion, to compile the number of Russian soldiers who have died. Their count is based on verified names in obituaries, cemetery burials, social media reports from relatives, probate records and other Russian state data.

The outlets updated their tally of verified Russian deaths to 200,186 but emphasized that the figure “remains a conservative floor, not a ceiling.” They identified nearly 27,000 Russian cities, towns and villages that sent soldiers to Ukraine who were ultimately killed.

The Center for Strategic and International Studies, based in Washington, recently said that Russia had suffered up to 325,000 deaths on the battlefield. The number appears to be a reasonable projection, given the confirmed numbers from Mediazona and the BBC Russian Service, which do not fully capture battlefield deaths from 2025 and 2026.

“No major power has suffered anywhere near these number of casualties since the Second World War,” said Seth Jones, the lead author of the center’s study, noting that one exception could be Chinese losses during the Korean War, though estimates from that conflict vary widely. “It is just short of shocking.”

The center’s study estimated the number of wounded and killed on the Russian side, often referred to together as casualties, to be as many as 1.2 million.

Fourth Anniversary of the War

On Tuesday, Putin marked the fourth anniversary of the war with a speech to the Federal Security Service, or FSB. He said that the Russian intelligence service needed to do more to protect the Russian homeland from Ukrainian attacks. A day earlier, Putin met with widows of fallen soldiers at the Kremlin.

In Ukraine, President Volodymyr Zelenskyy delivered an address highlighting Ukrainians’ perseverance, hosted senior European leaders in Kyiv and visited a makeshift memorial in the capital’s central square, where he said he hoped that President Donald Trump would visit the country to see its suffering.

Authorities in Ukraine, like Russian officials, have been secretive about army losses. Ukraine has restricted access to demographic data that could help estimate the number of Ukrainians killed in action, and it has released casualty figures in the tens of thousands that most observers consider understated.

The Center for Strategic and International Studies report estimated that 500,000 to 600,000 Ukrainian troops have been wounded, have been killed or have gone missing since the start of the war. The report said that 100,000 to 140,000 of those were fatalities, roughly two to three times higher than figures released by Zelenskyy earlier this month.

Kyiv has struggled to make up for losses as its army conscription system falls behind and desertions further strain manpower. Ukrainian officers say they cannot properly man their defensive lines as a consequence.

Russia Manages to Replace Losses

By contrast, Russia has largely managed to replace its losses with a recruitment system that relies on big enlistment bonuses and signing up convicts. Russia’s wartime population is also more than four times that of Ukraine.

“The big issue the Ukrainians face is numbers right now,” Jones said. “There is no question about it.”

To offset this disadvantage, Ukraine has sought to inflict losses on enemy forces at a rate equal to or greater than what Russia can replace. While that goal proved elusive for much of the war, Ukrainian and European officials say the balance may now be shifting.

Pavlo Palisa, a Ukrainian colonel and presidential adviser, said this week that Russia lost 120 troops for every square kilometer gained in 2025.

Mykhailo Fedorov, the Ukrainian defense minister, said that Ukraine had killed or seriously wounded 35,000 Russian soldiers in December. That is about as much as Russia’s average monthly recruitment last year, based on data released by Russian officials.

Fedorov said Ukraine aimed to raise the number of Russian losses to 50,000 per month. “The objective is to impose costs on Russia that it cannot bear,” he told reporters in January.

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This article originally appeared in The New York Times.

By Paul Sonne and Constant Méheut/Mauricio Lima
c. 2026 The New York Times Company