"From an expert point of view, it is an extremely superficial and incorrect judgment," Peskov told Russian journalist Pavel Zarubin.
A nuclear propulsion system and a nuclear explosion are completely different topics, Peskov added.
"First of all, we are talking about a delivery system, not a nuclear explosion. It is a nuclear-powered propulsion system or engine, so these are completely different matters," the spokesman said.
The Burevestnik and Poseidon are breakthrough technologies that other countries may develop them too, but not anytime soon, adding that their development involved large teams of talented individuals.