Former U.S. Ambassador Roger Noriega said, “Venezuelan strongman Hugo Chavez and Iranian leader Mahmoud Ahmadinejad are conspiring to wage an asymmetrical struggle against U.S. security, and to abet Iran’s illicit nuclear program.”

Noreiga noted that President Chavez has been stricken with cancer, and urged strong U.S. engagement with Venezuela in any post-Chavez era.

Iranian influence is but one of many topics requiring U.S. attention in Latin America, according to Latin America expert Cynthia Arnson, who had a recommendation for senators.

“That we not allow this issue [Iranian influence] to overshadow attention to the broader dynamics in the hemisphere, which are marked by economic growth, the fight against poverty and inequality, the emergence of Brazil,” Arnson said.

But Iranian plots in the hemisphere span decades and merit U.S. attention, according to Senator Rubio.

“Let us remember that it was senior Iranian officials that were linked to the 1992 bombing of the Israeli embassy in Buenos Aires that killed 30 people, a 1994 bombing at the Argentine-Israeli Mutual Association that killed 85 people. In October, we uncovered a plot by the Quds Force to assassinate the Saudi Arabian ambassador in the United States - in this very city,” Rubio said.

During a visit to Caracas last month, President Ahmadinejad described U.S. concern about Iran’s engagement with Latin America as "laughable." President Chavez said it is the United States -- not Iran -- that is a true threat to international security.