UNITED NATIONS - Irans UN ambassador has flatly denied US allegations of a plot to kill the Saudi ambassador to Washington as the work of the American warmongering and propaganda machine against Iran that threatened stability and peace in the Persian Gulf. In a letter to UN Secretary-General Ban Ki-moon released Wednesday, Ambassador Mohammad Khazaee described the US move as an evil plot against Iran. In his letter, the Iranian ambassador also accused Israel of carrying out the murders of Iranian nuclear scientists with US support. Iran categorically and in the strongest terms condemns this shameful allegation by the US authorities and deplores it as a well-thought evil plot in line with their anti-Iranian policy, Khazaee said. Iran has always condemned terrorism in all its forms and manifestations, and has been a victim, the ambassador wrote. The envoy asked Ban: As the UN secretary-general, you have an important responsibility in enlightening the international public opinion about the dangerous consequences of warmongering policies of the US government on international peace and security. AFP adds: Iranian Foreign Minister Ali Akbar Salehi on Wednesday warned the US against confrontation over accusations Tehran plotted to assassinate the Saudi ambassador to Washington. We are not seeking confrontation; our policy is cooperation and interaction. If they want to impose a confrontation upon the Iranian nation, the consequences of this issue will be more severe for them, Salehi told reporters after a cabinet session, the ISNA news agency reported. We do not want confrontation. (But) if they want to confront us and impose something on us, it will be the end of them. If they have the power to throw a punch, we have the power to smack (them) in a way that they would not be able to stand up, Salehi said. US authorities said Tuesday that two Iranians - one also holding US citizenship - were part of a plot conceived, sponsored and directed from Iran to kill Saudi Ambassador Adel al-Jubeir in a bomb attack. Iranian officials have rejected the accusations as mischievous, insisting Tehran had no part in the plot, which they said was a ploy to divert attention from US woes at home and in the Middle East. A former chief of Saudi intelligence, Prince Turki al-Faisal, said Wednesday there was overwhelming evidence that Tehran was behind the plot and warned somebody in Iran must pay the price.