A Ukrainian civic group said it has confirmed the deaths of nearly 25,000 Ukrainian soldiers since Russia's February 2022 invasion by using open sources, and puts the total toll at more than 30,000.
Kyiv treats its losses as a state secret and officials say disclosing the figure could harm its war effort. A report in August by the New York Times, citing anonymous US officials, put the Ukrainian death toll at close to 70,000.
Writing in the Ukrainian journal Tyzhden, historian Yaroslav Tynchenko and volunteer Herman Shapovalenko said Shapovalenko's Book of Memory project had confirmed 24,500 combat and non-combat deaths using open sources.
The real figure was likely higher, they added, noting that many of the 15,000 troops listed as missing were likely dead.
Reuters could not independently verify the figures.
"Obviously, the 24,500 names are not the final number of dead (deceased), but by our assessment it is no less than 70%," the authors wrote. "That is, the real number of dead (deceased) in combat and non-combat situations is more than 30,000 people."
Applying a 1:3 ratio, the authors also estimated that up to 100,000 troops had been wounded.
A spokesman for Ukraine's defense ministry told Reuters he could not comment on the figures.
The Book of Memory project, which has tracked Ukraine's war dead since Russia's first invasion in 2014, did not immediately respond to a request for comment.
Tynchenko, in a message through his employer, the National Military History Museum of Ukraine, declined to comment on the article.
The article, published late on Tuesday, comes as Ukraine increasingly faces the prospect of fighting a long war with Russia.
Ukraine's top general wrote in the Economist earlier this month that the conflict was becoming static and attritional. A Ukrainian counteroffensive launched in June has made only incremental gains in the south and east.
The authors of the Tyzhden article said it was crucial to balance various estimates reported in Western media, which they described as given to "manipulation", with verifiable data.
"Should we talk about this topic in Ukraine during the war? We believe so, but only in terms of concrete data and open and trustworthy sources," they wrote.
Russia has also not disclosed the number of its war dead.
