Iran has called the United States a “nuclear criminal” and says the country should be suspended from the United Nations' International Atomic Energy Agency (IAEA).

The comments were made at the opening of its own conference on nuclear disarmament, just days after a smiliar gathering in the US capital Washington held. The conference in Tehran is being attended by a few foreign ministers and UN officials.

Iran says the US is not the only country to have used nuclear weapons in conflict. It accused Iraq of having used weapons containing nuclear waste, but gave no further explanation.

Washington suspects Iran of developing nuclear weapons, but Tehran denies this.