The International Atomic Energy Agency passed a resolution that voiced "serious concern" regarding Iran's lack of cooperation with international demands to curb uranium enrichment and open up on its nuclear program.
Representatives from Russia and China joined a group of four Western nations led by the US in voting for the resolution at the IAEA's headquarters in Vienna on Thursday.
Cuba was the only country to vote against the measure, while Egypt, Ecuador and Tunisia - all members, along with Iran, of the Non-Aligned Movement - abstained.
The resolution calls on Iran to immediately agree to let UN inspectors into the country for checks on its nuclear facilities. Iran claims its nuclear program is for civilian purposes only, but there are concerns Iran could be trying to develop an atomic bomb.
Israel has been particularly blunt in its criticism of Iran, saying if Iran wants to avoid military action it had better be more forthcoming about is nuclear program. The country's prime minister, Benjamin Netanyahu, has recently called for "red lines" to be established with regard to how long Iran could continue to defy UN Security Council resolutions that demand Iran halt uranium enrichment.
The 35-member IAEA said in the resolution that it was keen to find a diplomatic solution to the problem.
In response to the IAEA resolution, Iran's representative on the UN body said the measure was counterproductive.
"It will only complicate the situation and jeopardise the cooperative environment which we desperately need," Ali Asghar Soltanieh said on Thursday.
The US envoy to the IAEA, Robert Wood, said the resolution sent a clear signal to Iran that "diplomatic pressure is intensifying" and the country's "isolation is growing."
The US and the European Union have also issued sanctions targeting Iran's oil sector.
"The time right now is for compliance over defiance and Iran needs to comply now with its obligations," Wood said. "We hope that Iran will hear and understand the message and begin to cooperate with the agency."
mz/dr (AFP, dpa, Reuters)