"Your presence in the Persian Gulf is the source of insecurity in this very sensitive region of the world," Khamenei said to the Americans during a speech in the southern city of Shiraz carried by state television.
"The security of this region has to be restored by regional countries," he insisted, adding that in the case of Iraq "the very presence of US forces is enough to provoke Iraqi people."
"In Palestine, American intervention has only worsened the situation," said the all-powerful leader, condemning US support for the Jewish state which Iran does not recognise.
"The situations in Iraq and in Palestine will be sorted out, but when these are resolved there will not be anything left of America's prestige and identity," the state broadcaster's website also quoted Khamenei as saying.
Washington accuses Iran of supporting terrorism and fomenting sectarian violence in Iraq. Tehran vehemently denies the charge and blames the presence of US-led opposition forces for the bloodshed in its western neighbour.
The two states are also at odds over Iran's controversial nuclear programme, which the United States says is cover for an atomic weapons drive. Iran denies it wants the bomb and insists that its nuclear ambitions are purely peaceful.
