Videos and photos show the bodies of soldiers left behind on the battlefield, officials say, and the charred remains of tanks and armored vehicles.
But Moscow may be losing that many soldiers daily in Mr. Putin’s latest invasion of Ukraine, American and European officials said. The mounting toll for Russian troops exposes a potential weakness for the Russian president at a time when he is still claiming, publicly, that he is engaged only in a limited military operation in Ukraine’s separatist east.
No one can say with certainty just how many Russian troops have died since last Thursday, when they began what is turning into a long march to Kyiv, the capital. Some Russian units have put down their arms and refused to fight, the Pentagon said Tuesday. Major Ukrainian cities have withstood the onslaught thus far.
The Russian Defense Ministry spokesman, Maj. Gen. Igor Konashenkov, acknowledged on Sunday for the first time that “there are dead and wounded” Russian troops but offered no numbers. He insisted Ukrainian losses were “many times” higher. Ukraine has said its forces have killed more than 5,300 Russian troops.
Neither side’s claims have been independently verified, and Biden administration officials have refused to discuss casualty figures publicly. But one American official put the Russian losses as of Monday at 2,000, an estimate with which two European officials concurred.
Senior Pentagon officials told lawmakers in closed briefings on Monday that Russian and Ukrainian military deaths appeared to be the same, at around 1,500 on each side in the first five days, congressional officials said.
For a comparison, nearly 2,500 American troops were killed in Afghanistan over 20 years of war.
For Mr. Putin, the rising death toll could damage any remaining domestic support for his Ukrainian endeavors. Russian memories are long — and mothers of soldiers, in particular, American officials say, could easily hark back to the 15,000 troops killed when the Soviet Union invaded and occupied Afghanistan, or the thousands killed in Chechnya.
Russia has deployed field hospitals near the front lines, say military analysts, who have also monitored ambulances driving back and forth from Russian units to hospitals in neighboring Belarus, Moscow’s ally.
“Given the many reports of over 4,000 Russians killed in action, it is clear that something dramatic is happening,” said Adm. James G. Stavridis, who was NATO’s supreme allied commander before his retirement. “If Russian losses are this significant, Vladimir Putin is going to have some difficult explaining to do on his home front.”
In particular, Pentagon officials and military analysts said it was surprising that Russian soldiers had left behind the bodies of their comrades.
“It’s been shocking to see that they’re leaving their fallen brethren behind on the battlefield,” said Evelyn Farkas, the top Pentagon official for Russia and Ukraine during the Obama administration. “Eventually the moms will be like, ‘Where’s Yuri? Where’s Maksim?’”
Already, the Ukrainian government has begun answering that question. On Sunday, authorities launched a website that they said was meant to help Russian families track down information about soldiers who may have been killed or captured.
The name of the site, 200rf.com, is a grim reference to Cargo 200, a military code word that was used by the Soviet Union to refer to the bodies of soldiers put in zinc-lined coffins for transport away from the battlefield; it is a euphemism for troops killed in war.
On Monday, Ukraine’s ambassador to the United Nations, Sergiy Kyslytsya, read out before the General Assembly what he said were the final text messages from a Russian soldier to his mother. They were obtained, he said, by Ukrainian forces after the soldier was killed. “We were told that they would welcome us and they are falling under our armored vehicles, throwing themselves under the wheels and not allowing us to pass,” he wrote, according to Mr. Kyslytsya. “They call us fascists. Mama, this is so hard.”
On Tuesday, a senior Pentagon official said entire Russian units have laid down their arms without a fight after confronting surprisingly stiff Ukrainian defense. In some cases, Russian troops have punched holes in their vehicles’ gas tanks, presumably to avoid combat, the official said.
On Monday, Ukraine’s defense minister, Oleksiy Reznikov, offered Russian soldiers cash and amnesty if they surrendered.
“Russian soldier! You were brought to our land to kill and die,” he said. “Do not follow criminal orders. We guarantee you a full amnesty and 5 million rubles if you lay down your arms. For those who continue to behave like an occupier, there will be no mercy.”
