Originally Posted by SoFlyOn

There's also the slight possibility that you may be denied boarding in the US (if intending to enter Argentina as a tourist), if you won't be able to show onward travel before 90 days. The airline is quite within it's rights to do this. At least up till now, it's been easy to extend your tourist visa for another 90 days by going to immigration (there's an office in downtown BsAs) and paying a small fee. However as NYTango points out, with the upcoming reciprocity fee staring on Jan01, things might get more complicated.

John