Russia is conducting a special operation in Ukraine to protect its citizens from nuclear war, including against nuclear-armed NATO countries, Kremlin spokesman Dmitry Peskov said on Thursday, Vechernyaya Moskva reported.

"Imagine a situation where a NATO member, Ukraine, thinking about the return of Crimea, attacks Russia and Russia's Crimea. Applying Article Five of the NATO Charter, the nuclear-armed NATO countries would have to defend Ukraine, there could be a third world war," he said.

Peskov noted that 'the special operation' in Ukraine is to protect Russia from the "potential threat of such a war," RIA Novosti reported.

Previously, the Kremlin spokesman said that Russian soldiers will liberate Mariupol from the Ukrainian National Security Forces in the near future. He also expressed hope that the operation of the Russian Armed Forces in Ukraine would end in the near future.

The presidential press secretary also said that Russia had suffered significant losses during the special military operation in Ukraine.

"We suffered significant troop losses, this is a huge tragedy for us," he said.