When these announcements are made, the troops are described as "NATO troops" because the announcement comes from NATO command, not the Pentagon. It may seem like a subtle point, but that's exactly why everything is presented this way when these announcements come out of Afghanistan.
To reinforce this point, I don't think troops in Iraq were ever described as "NATO troops" whenever reports like this came out.
Aren’t they all officially “NATO troops” in Afghanistan now? If this was an area where there were mostly Americans, probably these were American troops.
Frankly, I think Barry is using NATO troops as a dodge to cover up the fact that the vast majority of those Americans killed in Afghanistan were killed during his (much shorter) watch because of the ROE and because of his Taliban-friendly attitude.