Iran has demanded America's expulsion from the international nuclear system.
Iran's Supreme Leader Ayatollah Ali Khamenei used an international conference in Tehran to condemn the US as the "world's only atomic criminal".
"Only the US government has committed an atomic crime. The world's only atomic criminal lies and presents itself as being against nuclear weapons proliferation, while it has not taken any serious measures in this regard," said Ayatollah Ali Khamenei in a message read to the summit.
President Mahmoud Ahmadinejad called for the establishment of a new international weapons regime that would stand independent of Western political interference.
The Iranian government staged the meeting in response to President Barack Obama's summit on nuclear security in Washington at the start of the week.
Iran condemned the 47-nation disarmament summit in Washington on the grounds that the United States holds one of the world's largest arsenals of nuclear weapons.
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