The comments, carried by state television and radio, come amid prolonged tension between Washington and Tehran over Iran’s nuclear program. U.S. officials say Iran is trying to build an atom bomb but Tehran insists its plans are peaceful.
Iran has refused to halt sensitive nuclear work, despite U.S. threats to ratchet up pressure with new U.N. sanctions. Two rounds of sanctions have already been imposed since December.
“The political field of today’s world is a complicated field with a great war of wills and policies … It can be said that Iran has exploded a powerful bomb in the world of politics that is hundred times more powerful than the bomb the Americans exploded in Hiroshima,” Khamenei was quoted as saying.
“Even Europeans are speechless before this oppressive America, but the Iranian nation by its actions and stances has placed a question mark over all the rules and principles of this oppressive power.”
U.S. and Iranian officials are due to hold a rare face-to-face meeting on May 28 in Baghdad. But both sides say the talks will focus on Iraqi security, not other issues.
Washington accuses Tehran of fuelling the violence in Iraq, a charge Tehran dismisses. Iran blames the U.S. occupying forces for the bloodshed.
Khamenei is the highest authority in Iran under its system of clerical rule.
The United States dropped a nuclear bomb on Hiroshima and another on Nagasaki shortly before Japan surrendered at the end of World War Two.
It cut ties with Iran after the 1979 Islamic Revolution.
