President Mahmoud Ahmadinejad of Iran denies American claims his country was behind a plot to assassinate the Saudi Arabian ambassador in Washington.
Mr Ahmadinejad says the White House is trying to distract Americans from the country's economic problems.
He said the claims of a plot were as false as the allegations were about weapons of mass destruction in Iraq.
In an appearance on al-Jazeera he also said the United States was looking for an excuse to toughen sanctions against Iran.
He also accused Washington of trying to create divisions between Iran and Saudi Arabia, which is a US ally and Tehran's main rival in the Gulf.
Meanwhile, Saudi Arabia has asked the UN Security Council to look into what it called a ''heinous conspiracy''.
