President Vladimir Putin is set to lead a meeting of Russia’s Security Council on Wednesday focused on nuclear deterrence, according to the Kremlin. This comes as Moscow considers its response to Ukraine’s appeals to Western nations for permission to launch long-range strikes deep into Russian territory.

The ongoing conflict in Ukraine, now in its second and a half year, has resulted in the most significant tension between Russia and the West since the 1962 Cuban Missile Crisis, a period marked by the closest approach to nuclear conflict between the two superpowers during the Cold War.

Kremlin spokesperson Dmitry Peskov characterized the upcoming meeting as a significant occasion. “The president will deliver a speech. The remainder of the discussions will, for obvious reasons, be classified as ‘top secret’,” Peskov informed the media.

Russia has indicated that it is currently updating its nuclear doctrine, which outlines the scenarios under which it might consider using nuclear weapons. Additionally, Putin’s chief advisor on arms control stated on Monday that Russia would not conduct nuclear tests as long as the United States maintains its own testing moratorium, amid speculation that the Kremlin might reconsider its post-Soviet stance on nuclear testing.