The Ukrainian president said he would not give the number of wounded as that would help Russian military planning.
Typically, Ukrainian officials do not make casualty figures public, and other estimates are much higher.
It comes after the defence minister said half of all Western aid for Ukraine has been delayed, costing lives and territory.
Zelensky said that he was providing an updated death toll in response to the inflated figures that Russia has quoted.
Speaking about the wider losses in the war, Zelensky said tens of thousands of civilians had died in the areas of Ukraine occupied by Russia but the true number was unknown.
