in that same village, this ukrainian soldier on another captured tank claims victory. translator: the operation has been a complete success. we decisively repelled the enemy. reporter: there s no way to verify the soldier s claims. these battles exacting a dreadful civilian toll. this drone footage from irpin, bordering kyiv to the west, shows fires raging amid a tangle of burned-out, abandoned homes. the mayor telling cnn the town had come under heavy rocket fire. a senior u.s. defense official saying ukrainian forces are pushing the russians back in places like chernihiv, where buildings are seen on fire in this footage. i feel like just within days of ukraine really being able to get the momentum. reporter: on friday, the russian ministry of defense said about 1,350 russian military personnel have been killed so far in ukraine, but u.s., ukrainian, and nato estimates put those russian losses much higher. two senior nato officials this week estimating the number of russians k