Ahmadinejad was wrapping up his tour of Latin America this week with stops in countries including Venezuela, Ecuador and Cuba.
Rep. Ileana Ros-Lehtinen, R-Fla., chairwoman of the U.S. House Foreign Affairs Committee, said Ahmadinejad was embarked on a "tour of tyrants," adding Washington should strengthen its regional alliances in order to "confront the onslaught of anti-democratic forces in Latin America whose goal is to undermine our nation."
Her comments come as Washington and its European allies use economic sanctions to pressure Iran to abandon its perceived ambitions of developing a nuclear weapon. State Department officials said the purpose of the sanctions was to "tighten the noose" on Tehran.
Ahmadinejad was quoted by the official Islamic Republic News Agency as saying his Western adversaries were using the nuclear issue as "a political excuse."
Ahmadinejad called on "bullying powers" to respect the autonomy of the governments in Latin America, saying the United States was losing influence in the region.
"I want to declare officially that from now on, Latin America will no longer be the back yard of the United States," he said.