IAEA board approves resolution condemning Iran
The board of the International Atomic Energy Agency (IAEA) expressed "serious concern" about Tehran's refusal to suspend uranium enrichment, BBC reported.
Iran insists that its nuclear programme is peaceful in purpose but the US, Israel and other states fear it is building nuclear weapons.
Thirty-one out of 35 member states voted in favour of the resolution, one voted against and three abstained.
Cuba opposed the measure and Egypt, Ecuador and Tunisia abstained. All four countries are members of the Non-Aligned Movement, of which Iran is currently the rotating president.
Another member of the movement, South Africa, had introduced an amendment on a minor change of wording that resulted in a delay of several hours.
A total of six resolutions against Iran have been passed by the UN Security Council, four with sanctions attached.
The IAEA's resolution was proposed by the United States, China, Russia, Germany, France and the United Kingdom.
This move is a display of unity by the six world powers, says the BBC's Bethany Bell, in Vienna.
It also increases the pressure on Iran at a time when Israel has stepped up hints about a possible military strike, our correspondent adds.
The US and EU have also imposed additional, unilateral sanctions that have targeted Iran's vital oil exports.
Last weekend, EU foreign ministers said they were considering additional measures.
On Thursday, in its statement to the board, the 27-nation bloc described Iran's "procrastination" as "unacceptable".
"Iran has not engaged seriously and without preconditions in talks aimed at restoring international confidence in the exclusively peaceful nature of its nuclear programme," it said.
The IAEA has held a series of high-profile meetings with Iran that began in January to agree how to carry out its investigations.
But its Director General Yukiya Amano said this week that no concrete results had been achieved and called the lack of progress "frustrating".