The United Nation’s nuclear watchdog says Iran has worked on developing a nuclear weapon and on research and testing for such arms.
And, in its most detailed report to date, the International Atomic Energy Agency (IAEA) says such activities may be ongoing.
The United States and Israel are likely to use the document to press for more sanctions against Tehran.
But Iranian President Mahmoud Ahmadinejad dismissed the findings even before they were released saying: “The IAEA is just publishing reports provided by American officials. I am sorry the head of the IAEA, Yukiya Amano, is violating the agency’s regulations and is a puppet of America. Why doesn’t Mr Amano publish reports on the arsenals of America and its allies?”
Russia has already reacted, expressing disappointment over the report which it says will add to tension over the issue.
On Friday, Israeli President, Shimon Peres sparked alarm when he warned a military option to stop Iran from obtaining nuclear weapons was nearer.
The Islamic republic insists its nuclear programme is intended solely for domestic energy production.