Not buying it.
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.
Of Course there are NATO troops in Ukraine. Every SOF group in NATO has poured troops in Ukraine. And, all the sophisticated weaponry is being maintained by NATO troops.
The Pentagon has admitted there are US troops in country. It’s not a secret.