US President Barack Obama warned Iran the "world is watching" its actions, and said the United States stood with those seeking "peaceful" justice in the post-election tumult.
Obama appeared to send a nuanced message to opposition demonstrators hours after the Islamic Republic's supreme leader Ayatollah Ali Khamenei demanded an end to street protests.
Despite assurances by top officials that Washington would not inject itself into the crisis, both houses of the US Congress voted to condemn violence against demonstrators by the government of Iran.
"I'm very concerned based on some of the tenor - and tone of the statements that have been made - that the government of Iran recognize that the world is watching," Obama said in an interview with CBS News.
"And how they approach and deal with people who are, through peaceful means, trying to be heard will, I think, send a pretty clear signal to the international community about what Iran is and - and is not," Obama said in an interview with CBS.
Obama, who this month made a major address to the Muslim world from Cairo, said that the United States stood behind those in Iran who sought peaceful justice - but took pains to stress he was not intervening in the crisis.
Asked whether he had a message to the demonstrators, Obama replied "I absolutely do."We stand behind those who are seeking justice in a peaceful way.
"We stand with those who would look to peaceful resolution of conflict and we believe that the voices of people have to be heard, that's a universal value that the American people stand for and this administration stands for."
The president also attempted to debunk claims by some in the Iranian leadership that the opposition demonstrators were acting at the behest of the United States which has had a long history of antagonism with Iran.
"Let's understand that this notion that somehow these hundreds of thousands of people who are pouring into the streets in Iran are somehow responding to the West or the United States.
"That's an old distraction that I think has been trotted out periodically. And that's just not going to fly."
Obama emphasised: "This is not an issue of the United States or the West versus Iran; this is an issue of the Iranian people."
Obama's comments came as the crisis swiftly unfolded in Iran, a week after the disputed re-election of President Mahmoud Ahmadinejad drew claims from his rival Mir Hossein Mousavi of massive vote fraud.
Senior US officials earlier stressed that Washington was making strenuous efforts to avoid being drawn into the crisis - in a way that could be used by the government against the demonstrators.
"The more the United States looks like they are going to interfere, the more it is going to be detrimental," said one official on condition of anonymity.
"This is not about us."
Asked about the more vociferous criticisms of Iran by European powers, including France, an official said that those US allies did not have the same kind of tortured relationship with Iran that Washington did.
The House resolution, which passed by 405 votes to one, expressed "its support for all Iranian citizens who embrace the values of freedom, human rights, civil liberties, and rule of law."
It also "condemns the ongoing violence against demonstrators by the government of Iran and pro-government militias, as well as the ongoing government suppression of independent electronic communication through interference with the Internet and cell phones."
Democrat Howard Berman, chairman of the House Foreign Affairs committee, said the bill was not a "judgment on who won the Iranian elections."
"It is an acknowledgement that we cannot remain silent when cherished, universal principles are under attack."
A similar measure passed by voice vote in the Senate.
Khamenei demanded an end to protests that have rocked Tehran for the past week, warning that otherwise there could be further bloodshed beyond the seven deaths reported by state radio.For all the latest business news from the UAE and Gulf countries, follow us on Twitter and Linkedin, like us on Facebook and subscribe to our YouTube page, which is updated daily.
Subscribe to Arabian Business' newsletter to receive the latest breaking news and business stories in Dubai,the UAE and the GCC straight to your inbox.