I’m pretty sure he’s saying that the US is involved and that he’s American:
The US is not an active combatant but we’re supplying training, intelligence, armament, and probably food and other supplies. We probably have intelligence agents in the field and some advisors (though, that’s supposition not fact).
I don’t think we have anything to gain by helping Ukraine or otherwise really care about the country beyond that it’s been attacked. The supposed strategic position of it for NATO seems overstated given the existence of ICBMs, submarines, that NATO has other nations on the border with Russia already, and that - in general - our goal has been to not have to get into a war with anyone and for everyone to give up on 1800s style colonialism and just be happy in their own frickin borders. So to the extent that we are involved, I don’t see any reason to think it’s nefarious but we are certainly involved.