Russia will make changes to its nuclear doctrine in response to the West’s actions over the conflict in Ukraine, the TASS state news agency cited Deputy Foreign Minister Sergei Ryabkov as saying on Sunday.

Ryabkov did not say what the changes would entail.

Russia’s existing nuclear doctrine, set out in a decree by President Vladimir Putin in 2020, says it may use nuclear weapons in the event of a nuclear attack by an enemy or a conventional attack that threatens the existence of the state.

Russia, which accuses the West of using Ukraine as a proxy to wage war against it, has said before that it is considering changes. Ryabkov’s was the most categorical statement yet that it would proceed with them.

“The work is at an advanced stage, and there is a clear intent to make corrections”, TASS cited Ryabkov as saying. He said the decision is “connected with the escalation course of our Western adversaries” in connection with the conflict in Ukraine.