I think it is good advice to contact the embassy, but I have to correct the statement that you can't travel on Argentina residency. I am not a citizen of Argentina, I am a resident of Argentina and have traveled on my residency document for several years. Before, if I would offer both documents they either hand the US one back without looking at it, or they ask me which one I want to use.
I have seen several people post on this forum that you cannot travel on residency alone and that is 100% erroneous. I know people with Uruguay residency who have gone into Brazil without a visa on their residency document. However, some think it was just a lax border agent. If I were going to Brazil, just for fun I would try using only the Argentina document and see if it would work, but be prepared to get the visa if I had to.