Russia Says Western Actions Compel It to Boost Its Nuclear Deterrent

Ryabkov was cited by state news agency RIA as saying that Russia was not however changing its own nuclear doctrine, which allows for the use of nuclear weapons in case of an existential threat to the state, Reuters reported.

"At the moment, there are no changes in this regard. But the situation itself is changing, so how the basic documents in this area relate to the needs of ensuring our security is the subject of constant analysis," Ryabkov said.

"We warn our opponents that their escalatory trajectory confronts us of course with the need to take steps that actually mean strengthening our measures of deterrence."

He said exercises involving Russia's tactical nuclear weapons, announced by Moscow earlier this week, were part of those efforts.