"They are free to talk but their words do not have any validity. It is natural that if a word is right and just it will provoke a reaction," Ahmadinejad told the official news agency IRNA.
The straight-talking hard-liner, who won a shock election victory in June, went on to criticise "international Zionism and the expansionist policies of the world arrogance" - terminology usually used to refer to the United States and Israel.
"They are cheeky humans, and they think that the entire world should obey them.