Again I will repeat If I buy something or ship something in a country that is not the country of origin it is up to the customs officer, if they wish to investigate where the item was made. When you arrive and fill out the customs forms in the...
But is the seller responsibility to inform US Customs as to country of origin or country of purchase.
When traveling in the past i do not ever remember being asked what country was the item made in.
While I agree with this, if you were to order a drone from another country, at this point the amount of tariff you would pay is dependent on whether the custom agent charges the tariff of the shipping country or the country of origin of the product.