North Atlantic Treaty Organization (NATO) Secretary General Jens Stoltenberg claimed during a Jan. 31 event at the Heritage Foundation that the Russians have suffered over 300,000 casualties, lost thousands of armored vehicles and tanks, and over 100 aircraft since it invaded Ukraine in 2022.

NATO Secretary General on Modern Needs of the Alliance 75 Years After Its Founding https://t.co/IuXBfQbSpB

— Heritage Foundation (@Heritage) January 31, 2024

“Russia has lost more than 300,000 casualties, thousands of armored vehicles, half of their battle tanks, perhaps even more, and 100 of [its] aircraft,” Stoltenberg said near the end of the event.

There is a variety of estimates for Russian casualties. U.S. officials told The New York Times in August 2023 that Russia had likely suffered 120,000 dead and 180,000 wounded, equaling 300,000 casualties. Reuters reported in December 2023 that a declassified intelligence assessment stated that Russia had suffered 315,000 casualties.

The United Kingdom’s Ministry of Defense (MOD) assessed in December 2023 that Russia had suffered between 290,000 and 350,000 casualties, with 70,000 dead and 220-280,000 wounded. This is divided between the Russian Armed Forces and Wagner Group, a paramilitary group that fought extensively in Bakhmut.

Latest Defence Intelligence update on the situation in Ukraine – 4 December 2023.

Find out more about Defence Intelligence’s use of language: https://t.co/YagSaiekzW

🇺🇦 #StandWithUkraine 🇺🇦 pic.twitter.com/AkQ44Nj5Yj

— Ministry of Defence 🇬🇧 (@DefenceHQ) December 4, 2023

The Ukrainian Ministry of Defense (MOD) assessed that Russia had lost 385,230 personnel as of January 31, 2024, though it does not distinguish between killed and wounded. General Valery Zaluzhny, Ukraine’s top military commander, told The Economist in November 2023 that Russia had suffered at least 150,000 deaths.

A spokesperson for the Ukrainian Armed Forces told Check Your Fact in an email that the Russian personnel losses pertain to “the number of people wounded and killed” but do not include prisoners of war. (RELATED: Houthi Rebels Claim To Hit U.S. Warship In Red Sea)

Mediazona and BBC News Russian Service have documented 42,284 Russian deaths. Their standard “for confirmed deaths is stringent—it requires an official publication or social media post from a relative with corresponding details, accompanying photos or dates of burials from local messaging groups, or photos from cemeteries.”

The Ukrainian MOD claims the Russians have lost 6,310 Russian tanks and 11,757 armored vehicles  The UK MOD has also assessed that Russia likely lost 2,600 main battle tanks and 4,900 armored vehicles between February 24, 2022 and January 25, 2024. The declassified U.S. intelligence assessment found that Russia had lost 2,200 tanks and 4,400 armored vehicles, according to CNN.

There are also open-source intelligence assessments of Russian vehicle losses. Oryx, a military analysis website, has documented the loss of 2,700 tanks, with 1,769 destroyed, 149 damaged, 241 abandoned and 541 captured as of Feb. 2, 2024.

Oryx has also documented the loss of 1175 armored fighting vehicles (AFVs), 3353 infantry fighting vehicles (IFVs) and 392 armored personnel carriers (APCs) for a total of 4,920 armored vehicles that have been lost by Russian forces.

Oryx notes, “This list only includes destroyed vehicles and equipment of which photo or videographic evidence is available. Therefore, the amount of equipment destroyed is significantly higher than recorded here.”

WarSpotting has documented 2,330 tank losses for Russia, with 131 damaged, as of Feb. 2, 2024. It has also documented 4327 infantry fight vehicles, though it does not split the category into AFVs, IFVs and APCs like Ory . The numbers between Oryx and WarSpotting do differ.

WarSpotting addressed the differences between Oryx and WarSpotting in a series of June 2023 tweets.

People seem to keep wondering how and why Oryx and our list are different. Our numbers are considerably lower in most of the brackets, indeed. We thought it’s time to officially address the issue. As one might have guessed, there are reasons. Not one but five. 🧵 pic.twitter.com/Ctfm6bIY5F

— WarSpotting (@WarSpotting) June 20, 2023

WarSpotting also warns that its data cannot be trusted. (RELATED: Can The US Not Produce Missiles Anymore?)

“Photos can be forged or misattributed. On top of that amount of photos available online nowhere near reflects actual losses. Even so, it might still be closer to reality than any claims being made by any official across the board,” WarSpotting writes on its “About” page.

As for aircraft, Oryx has documented 93 aircraft losses, which include damaged and destroyed aircraft. Warspotting has documented 76 aircraft losses, including 64 destroyed and 12 damaged. The Ukrainian MOD has claimed Russia has lost 332 aircraft as of Jan. 31.

Check Your Fact has reached out to NATO, the National Security Council and the Pentagon for comment.