President Mahmoud Ahmadinejad on Sunday denied US allegations that Iran was involved in a plot to kill the Saudi envoy to Washington, insisting that "assassination belongs to you Americans."
"The cultured people of Iran do not need to resort to assassination," the state television website quoted Ahmadinejad as telling a gathering of schoolchildren in Tehran.
His comments reinforced fierce denials made by other Iranian officials since Washington first made the allegations on Tuesday.
On Saturday, Iran's supreme leader, Ayatollah Ali Khamenei, slammed the US accusations as "absurd."
Signup to our newsletter and follow us on Facebook and Twitter!
The Iranian government has also repeatedly accused the United States and Israel of being behind the assassinations of two of its nuclear scientists in the past two years.
Ahmadinejad said: "They (the United States) are trying hard to push the anti-Iran campaign and in this phase they have accused Iran of assassination, but we must make them understand that assassination is the work of an uncultured people.
"One day they impose a war, the next they impose economic sanctions and the next, political pressure," he added.
The United States has vowed to make Iran "pay a price" for the alleged plot. It is seeking to further isolate Iran by rallying allies and other nations to pile on added pressure.
Iran is already subject to UN and US economic sanctions over its controversial nuclear programme.