"We received a 50-fold increase in irretrievable combat casualties and sanitary losses this year", Matios said.
He attributed these losses to a significant decline in a military discipline among the servicemen.
Matios declined to elaborate on the exact number of losses, but admitted that they are substantial.
The spring of 2014 saw the beginning of a military operation against groups supporting the independence of the Donetsk and Lugansk regions in eastern Ukraine, which were then proclaimed the People's Republics.
After several months of fighting, which claimed the lives of thousands of people, a ceasefire agreement on eastern Ukraine was clinched in the Belarusian capital Minsk.