An alleged plot to kill a Saudi ambassador on American soil represents a "dangerous escalation" in Iran's support for terrorism, U.S. Secretary of State Hillary Clinton said Wednesday.

The United States claims to have disrupted a plot by Iranian agents to kill Adel al-Jubeir, the Saudi ambassador to America.

Iran has denied the allegations, but the U.S. is pointing a finger at Tehran and is urging the international community to help isolate the Iranian government and enact more sanctions against it.

Speaking at a conference in Washington on Wednesday, Clinton urged the rest of the world to back America's condemnation of the alleged plot against al-Jubeir's life.

Clinton called the plot a "reckless act" that "undermines international norms and the international system."

U.S. officials say Iranian agents reached out to a person they believed was connected to Mexican drug cartels earlier this year, as they sought to find someone to carry out the plot.

U.S. authorities allege that an Iranian-American citizen named Manssor Arbabsiar offered to pay up to $1.5 million for the proposed hit on al-Jubeir. And they claim he eventually wired $100,000 to an account as a down payment.

CTV's Washington Bureau Chief Paul Workman said that the money trail could help shed light on who may have been involved.

"It's intriguing when you think about it: If it's true that the Iranians were trying to buy hitmen in Mexico, through a drug cartel to come into Washington and blow up a restaurant and the Saudi ambassador at the same time, it really is just extraordinary," he said.

"And if you have this $100,000 being sent into an American bank account, that may help us to see who was involved with the Iranian side, if anybody, and how far it went up the chain of command."

Relative helped find recruit

Arbabsiar was arrested at New York's John F. Kennedy International Airport last month.

The 56-year-old Arbabsiar has spent years of his life living in Texas, where he previously was a partner in a used car business. Public records show he has been married at least twice.

A second Iranian citizen, identified by the U.S. as Gholam Shakuri, has also been charged in connection with the plot, though he is still at large in Iran.

It is believed that Arbabsiar was recruited for the plot by Abdul Reza Shahlai, a relative who is a high-ranking member of Iran's Quds Force, the Islamic republic's special foreign actions unit.

Stewart A. Baker, a former assistant secretary for policy in the U.S. Department of Homeland Security, said it appears Arbabsiar is "a little bit of a loser," who struggled to find success in life.

But the person who recruited Arbabsiar is "a very high-ranking member of the Quds Force in Iran and a very dangerous man," Baker told CTV's Canada AM on Wednesday.

Baker said the fact that the Quds Force allegedly sought out foreign muscle to carry out its dirty work is not unusual, as they have routinely used proxy agents to attack targets in the past.

And if the U.S. has proof that Iranian agents were behind the plot, he said Washington could easily justify making a retaliatory strike against Tehran.

"This is an act of war and the United States would be entitled to respond with pretty substantial force to deter Iran from carrying out plans of this sort in the future," Baker said.

With files from The Associated Press