Iran's Supreme Leader Warns U.S. of 'Resolute Response' Over Assassination Claims

TEHRAN, Iran (AP) -- Iran's supreme leader warned the United States on Sunday that any measures taken against Tehran over an alleged plot to assassinate the Saudi ambassador to Washington would elicit a "resolute" response.

Two men, including a member of Iran's special foreign actions unit known as the Quds Force, have been charged in New York federal court with conspiring to kill the Saudi diplomat, Adel Al-Jubeir. U.S. officials have said no one was ever in any immediate danger from the plot.

"If U.S. officials have some delusions, (they must) know that any unsuitable act, whether political or security, will meet a resolute response from the Iranian nation," state TV quoted Supreme Leader Ayatollah Ali Khamenei as saying.

Khamenei's comments may reflect Iranian concerns that Washington would use the Jubeir case to ratchet up sanctions and recruit international allies to try to further isolate Tehran.

U.S. Secretary of State Hillary Rodham Clinton has been blunt in saying the United States would use the allegations as leverage with other countries that have been reluctant to apply harsh sanctions or penalties against Iran.

President Barack Obama said Thursday that the U.S. will be able to support all of its allegations that Iran was directly involved in the plot.

(Related: Lawmakers on both sides of the aisle call Iranian plot an "act of war")

But Khamenei, who has the final say on all state matters in Iran, said that the U.S. accused Iran of terror in order to divert attention from its economic woes and from the Occupy Wall Street protest movement.

"By attributing an absurd and meaningless accusation to a few Iranians, they tried ... to show that Iran is a supporter of terrorism ... This conspiracy didn't work and won't work," he said.

Iran's President Mahmoud Ahmadinejad for his part dismissed U.S. accusations as a fabricated "scenario."

"Iran is a civilized nation and doesn't need to resort to assassination," Ahmadinejad was quoted by the official IRNA news agency as saying Sunday. "The culture of terror belongs to you," he said, addressing the United States.

Iranian officials have consistently denied the allegations since they first emerged last week. An earlier statement by Khamenei on Saturday, and Ahmadinejad's remarks on Sunday, were the first comments made by the country's two highest leaders.

In a formal statement released Saturday, the Iranian government said it has no connection to Manssor Arbabsiar, the man arrested in the alleged plot.

"Unilaterally announcing accusations without showing documentation and creating a media wave against Iran is in no way compatible with legal logic, and can only be a purely media and political show," it said.

Arbabsiar is a 56-year-old naturalized U.S. citizen who also had an Iranian passport. In May 2011, the criminal complaint says, he approached someone he believed to be a member of the vicious Mexican narco-terror group, Los Zetas, for help with an attack on a Saudi embassy. The man he approached turned out to be an informant for U.S. drug agents, it says.

The U.S. charges that Arbabsiar had been told by his cousin Abdul Reza Shahlai, a high-ranking member of the Quds Force, to recruit a drug trafficker because drug gangs have a reputation for assassinations.

Iranian lawmakers and analysts have said Iran would not benefit from killing the Saudi ambassador in Washington, and thus has no reason to do so.