The astir elder US wide estimates that astir 100,000 Russian and 100,000 Ukrainian soldiers person been killed oregon injured successful the warfare successful Ukraine.
Gen Mark Milley, president of the US Joint Chiefs of Staff, besides suggested that astir 40,000 civilians had died aft being caught up successful the conflict.
The estimates are the highest offered yet by a Western official.
But helium observed that signs Kyiv was consenting to re-enter talks with Moscow offered "a window" for negotiations.
In caller days, Ukraine has signalled a willingness to clasp immoderate discussions with Moscow, aft President Volodymyr Zelensky dropped a request that his other number, Vladimir Putin, indispensable beryllium removed from powerfulness earlier negotiations could resume.
But speaking successful New York, Gen Milley added that for immoderate talks to beryllium successful, some Russia and Ukraine would person to scope a "mutual recognition" that a wartime triumph "is possibly not achievable done subject means, and truthful you request to crook to different means".
The apical wide - who serves arsenic President Joe Biden's astir elder subject advisor - said the standard of the casualties could person some Moscow and Kyiv of the request to negociate implicit the coming wintertime months, erstwhile warring whitethorn dilatory owed to freezing conditions.
"You're looking astatine good implicit 100,000 Russian soldiers killed and wounded," Gen Milley said. "Same happening astir apt connected the Ukrainian side."
Both Ukraine and Russian jealously defender their casualty numbers.
Moscow's past update successful September - the archetypal issued since March - said that conscionable 5,937 troops had been killed since the commencement of the conflict, with Defence Minister Sergei Shoigu dismissing reports of a importantly higher decease toll.
"There has been a tremendous magnitude of suffering, quality suffering," said Gen Milley. He besides also noted that betwixt 15 and 30 cardinal refugees person been created since Russia launched its penetration connected 24 February.
The UN has recorded 7.8 cardinal radical arsenic refugees from Ukraine crossed Europe, including Russia. However, the fig does not see those who person been forced to fly their homes but stay successful Ukraine.
On Wednesday, Moscow announced its troops would commencement to retreat from the cardinal confederate metropolis of Kherson - the lone large metropolis to autumn to Russian forces.
Gen Milley said that portion "initial indicators" suggested that a retreat had begun, helium observed that Russia had amassed astir 20-30,000 troops successful the city, and the withdrawal could instrumentality respective weeks.
"They made the nationalist announcement they're doing it. I judge they're doing it successful bid to sphere their unit to re-establish antiaircraft lines southbound of the [Dnieper] river, but that remains to beryllium seen," helium said.