Oct. 13, 2011  -- President Barack Obama said today that Iran will "pay a price" through sanctions and international pressure for its recent hostile behavior including the alleged Iran-directed plot to assassinate the Saudi Arabian ambassador to the U.S. in Washington, D.C.

Echoing previous statements by top U.S. officials, Obama said that when dealing with Iran, "We don't take any options off the table," but did not make any mention of possible military action in favor of pushing harsh economic sanctions and corralling international condemnation of Iran's alleged action.

"We're going to continue... to mobilize the international community to make sure that Iran is further and further isolated and pays a price for this kind of behavior," Obama said.

Obama declined to comment on whether he believed the highest levels of the Iranian government were aware or involved in the alleged plot, but said even if the Iranian president or supreme leader did not have "detailed operational knowledge, there has to be accountability with respect to anybody in the Iranian government engaging in this kind of activity."

READ: President Obama on Alleged Iranian Plot: 'There Has to Be Accountability'

U.S. Attorney General Eric Holder announced Tuesday the DEA and FBI had disrupted a plot "conceived, sponsored and... directed from Iran" to murder the Saudi Arabian ambassador to the U.S. in or outside a crowded Washington, D.C. restaurant which potentially would have been followed up by bombings of the Saudi Arabian and Israeli embassies. The U.S. said an Iranian-American, 56-year-old Manssor Arbabsiar of Corpus Christi, Texas, was working for elements of the Iranian government -- specifically Iran's elite military unit the Quds force -- when he attempted to hire hitmen from the feared Zetas Mexican drug cartel to carry out the hit, but Arbabsiar was unwittingly speaking to a DEA informant from the start.

READ: U.S. Complaint in Alleged Iran-Directed Terror Plot (PDF)

The U.S. Treasury Department announced Tuesday sanctions against five Iranians allegedly tied to the plot and additional sanctions Wednesday against an airline company allegedly linked to the Quds force. U.S. representatives began Wednesday meeting separately with members of the United Nations Security Council as part of the American government's effort to "unite world opinion" against Iran, in the words of Vice President Joe Biden.

A lawyer for Arbabsiar has not returned requests for comment, but the man's wife, Martha Guerrero, said he was wrongly accused.

"I may not be living with him being separated, but I cannot for the life of me think that he would be capable of doing that," she told ABC News' Austin affiliate KVUE Tuesday, noting the two had been separated some time. "He was at the wrong place at the wrong time. I'm sure of that."

Iranian officials have strongly rejected the U.S. accusations, calling them a "fabrication." The head of the Iranian mission to the United Nations penned a letter Tuesday to U.N. Secretary General Ban Ki-moon expressing "outrage" at the allegations.

"The U.S. allegation is, obviously, a politically-motivated move and a showcase of its long-standing animosity towards the Iranian nation," the letter says. "The Islamic Republic of Iran categorically and in the strongest terms condemns this shameful allegation by the United States authorities and deplores it as a well-thought evil plot in line with their anti-Iranian policy to divert attention from the current economic and social problems at home and the popular revolutions and protests against United States' long supported dictatorial regimes abroad."

Alleged Terror Plotter Claims He Was 'Directed By High-Ranking' Iranian Officials

The case, called Operation Red Coalition, began in May when Arbabsiar unwittingly approached a DEA informant seeking the help of a Mexican drug cartel to assassinate the Saudi ambassador, according to counter-terrorism officials.

Arbabsiar reportedly claimed he was being "directed by high-ranking members of the Iranian government," including a cousin who was "a member of the Iranian army but did not wear a uniform," according to a person briefed on the details of the case.

Arbabsiar and a second man, Gohlam Shakuri, an Iranian official, were named in a five-count criminal complaint filed Tuesday afternoon in federal court in New York. They were charged with conspiracy to kill a foreign official and conspiracy to use a weapon of mass destruction, a bomb, among other counts. Shakuri is still at large in Iran, Holder said.

Holder identified Shakuri as an Iran-based member of the Quds force.

Arbabsiar, a naturalized U.S. citizen, expressed "utter disregard for collateral damage" in the planned bomb attacks in Washington, according to officials.

The complaint describes a conversation in which Arbabsiar was allegedly directing the informant to kill the Saudi ambassador and said the assassination could take place at a restaurant. When the informant feigned concern about Americans who also eat at the restaurant, Arbabsiar said he preferred if bystanders weren't killed but, "Sometimes, you know, you have no choice, is that right?"

U.S. officials said Arbabsiar met twice in July with the DEA informant in the northern Mexico city of Reynosa, across the border from McAllen, Texas, and negotiated a $1.5 million payment for the assassination of the Saudi ambassador. As a down payment, officials said Arbabsiar wired two payments of $49,960 on Aug. 1 and Aug. 9 to an FBI undercover bank account after he had returned to Iran.

Officials said Arbabsiar flew from Iran through Frankfurt, Germany, to Mexico City Sept. 29 for a final planning session, but was refused entry to Mexico and later put on a plane to New York, where he was arrested.

Officials said Arbabsiar is now cooperating with prosecutors and federal agents in New York, where the case has been transferred.

"Though it reads like the pages of a Hollywood script, the impact would've been very real and many lives would've been lost," FBI Director Robert Mueller said of the foiled plot.

ABC News' Richard Esposito, Rym Momtaz and Kirit Radia contributed to this report.

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