NATO countries that have approved strikes with their weapons on Russian territory should be aware that their equipment and specialists will be destroyed not only in Ukraine, but also at any point from where Russian territory is attacked, Russia’s Security Council’s Deputy Chairman Dmitry Medvedev said on his Telegram channel, noting that the participation of NATO specialists could be seen as a casus belli.

"All their military equipment and specialists fighting against us will be destroyed both on the territory of former Ukraine and on the territory of other countries, should strikes be carried out from there against Russian territory," Medvedev warned, Tass reported. 

He added that Moscow proceeded from the fact that all long-range weapons supplied to Ukraine were already "directly operated by servicemen from NATO countries", which is tantamount to participation in the war against Russia and a reason to start combat operations.

Medvedev added Russia was not bluffing when it spoke of the possibility of using tactical nuclear weapons against Ukraine and warned Moscow's conflict with the West could escalate into all-out war.