Iran's president has said US claims of a plot to assassinate a Saudi ambassador are as fake as its allegations were about weapons of mass destruction in Iraq.
Mahmoud Ahmadinejad said,” the US had hoped to make people forget about its "internal economic problems".
In an appearance on al-Jazeera he also said the US was looking for an excuse to toughen sanctions against Iran.
Saudi Arabia meanwhile asked the UN Security Council to look into what it called a "heinous conspiracy".
Secretary General Ban Ki-moon said he had passed correspondence about the affair to the Security Council.