Your IDL will only be useful (together with your national license, it can't be used separately) for your first 6 months in Argentina.
After that you need a valid Argentinian driving license.
You can exchange your foreign national driving license for an Argentinian one only if your license is Italian, Spanish, or also it seems Chilean. Argentina doesn't exchange licenses of any other country. Search for "canje de licencia" to get more information.
So if you can't take advantage of the exchange agreements, you need to get an Argentinian DL, which includes taking the theoretical and practical driving tests. If you can get a legalized, translated copy of your foreign DL that's less than 3 months old when you go to get your Argentinian DL, you may be able to skip the probationary period (not allowed on roads with >70km speed limit). The exact procedure for getting the Argentinian DL varies according to the province.