Latin America expert Stephen Johnson says countries Ahmedinejad did not visit are taking heed of the nuclear question.

"This is something that’s, I think, troubling to countries like Brazil and Argentina, and many other countries in Latin America, which happen to be signatories of the Treaty of Tlatelolco and are nuclear non-proliferation countries," said Johnson.

And while Ahmadinejad's government has signed trade and business agreements with the Iran-friendly bloc, many projects are plagued by delays and face criticism as being unnecessary.