The combat medic, whose volunteer team has been described as "medical angels" by the Western media, said "cockroaches" don't deserve the right to procreate, RT reported.
The shocking declaration came from Gennadiy Druzenko, a constitutional lawyer-turned-volunteer frontline medic in Ukraine.
Speaking to Ukrainian media in a live interview, he condemned the US for its reluctance to go to war with Russia on Ukraine's behalf, before commenting on the Russian military.
"Trust me, (Russian President Vladimir) Putin's military hardware burns well. The corpses of ‘putinoids' may stink, but they become unthreatening," the report quoted him saying.
Druzenko said that during the conflict, he had diverged from the principle that requires an injured enemy combatant to be treated as a regular patient.
He further implied that at the hands of his unit, Russian prisoners of war "will die in very large numbers" so that surviving Russians remember Ukraine with terror "like the Germans remembered Stalingrad", RT reported.
Druzenko heads the Pirogov First Volunteer Mobile Hospital, a unit of civilian medics that has been providing services to Ukrainian troops since 2014, when post-coup authorities in Kiev sent the Ukrainian military to quash a rebellion in eastern Ukraine.
He is an acclaimed figure at home and has received numerous awards for his work from the defence ministry and the National Security Council, the report said.