The United States said on Saturday Iran was now locked in "unprecedented" isolation after UN bodies overwhelmingly condemned its nuclear programme and an alleged Tehran-planned terror plot.
US National Security Advisor Tom Donilon said that US policy to turn Iran into a pariah state over its behaviour was working and that Tehran was now crucially losing support from Arab and Muslim nations.
"It is the case I think, that the isolation that Iran is undergoing right now... really is unprecedented," Donilon told reporters in Indonesia on the final day of President Barack Obama's Pacific tour.
"They see themselves wholly isolated."
On Friday, the UN atomic energy agency's board passed a resolution condemning Iran's nuclear activities after a damning recent report by the watchdog.
"Thirty-two countries voted a resolution asking the Iranians to meet their obligations," Donilon, said, pointing out that the vote came after Obama had raised Iran in talks last week with the presidents of Russia and China -- which have expressed scepticism about more sanctions on Tehran.
The United Nations General Assembly meanwhile passed a resolution demanding that Iran cooperate with an investigation into the alleged plot by Iranian government officials to assassinate the Saudi envoy to Washington.
"That vote yesterday was 106 to nine, and notably -- and this, I think, is critical -- there wasn't one Arab or Muslim country that voted with the Iranians," Donilon said.
Despite Washington's satisfaction at the new blows to Iran by the international community, the prospects for new UN sanctions remain unclear.
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Obama did not appear to make noticeable progress towards that end during his talks with Chinese President Hu Jintao and Russian President Dmitry Medvedev.
If the UN route is blocked, the US and its allies plan to stiffen measures against Iran themselves, with Tehran's petrochemical sector and financial system possible targets.
The International Atomic Energy Agency resolution said it was "essential for Iran and the agency to intensify their dialogue" and called on Tehran "to comply fully and without delay with its obligations under relevant resolutions of the UN Security Council".
Only Cuba and Ecuador on the 35-nation IAEA board of governors voted against the resolution and Indonesia abstained.
To assuage Chinese and Russian misgivings, the resolution has no timeframe for Iran to comply, calling instead for IAEA head Yukiya Amano to report to the board in March on Tehran's "implementation of this resolution".
Last week, the IAEA came as close as it ever has to accusing Iran outright of seeking to develop nuclear weapons, in a report immediately rejected by the Islamic republic as "baseless."
At the UN General Assembly on Friday, the Saudi resolution on the alleged plot to assassinate its envoy to Washington was passed with 106 votes in favour, nine against and 40 abstentions.
The United States accuses Iran of masterminding the plot, while Tehran strongly denies involvement.
Iran's ambassador Mohammad Khazaee called the resolution "mind-boggling" as nobody had yet been found guilty in court of organising a plot.
China voted against the resolution and Russia, Brazil, South Africa and India were among UN Security Council members who abstained.