Iran's supreme leader, Ayatollah Ali Khamenei, dismissed Saturday US allegations of a Tehran-sponsored assassination plot as "absurd," in his first direct reaction to the claim.
"It's a meaningless and absurd accusation regarding a number of Iranians," he told a crowd in the western city of Gilangharb in a speech carried by state television.
"But it has not stuck and it will not stick," he said.
Khamenei said of the United States: "They say that they want to isolate Iran. They are the ones who are isolated."
His comments reinforced fierce denials of involvement made by other Iranian officials ever since the US accusation was made public Tuesday.
US officials have said they have evidence that the alleged plot to assassinate the Saudi ambassador to the United States was ordered and supported by Iranian officials, but admit they do not know which leaders, if any, are implicated.
The US Justice Department and FBI say the trail leads to officials inside the Quds Force, a special operations outfit within Iran's elite Revolutionary Guards that reports directly to Khamenei.