However , given the circumstances, it is very possible that Ukraine is using foreign mercenary troops. If their objective actually is the Russian nuclear power plant this could be a real problem. The Ukraine seems to be trying to widen the war and draw NATO into directly into the fight and this is one way to accomplish this.
The posted tweet says that the attack is being led by NATO. That’s not the same as claiming mercenary troops. I don’t buy that NATO is directly involved in military action as the Russian said. Mercenaries? Who knows?