By Paul Reynolds
World affairs correspondent, BBC News website
Iran has insisted it will not stop enriching uranium
The latest criticism of Iran by the International Atomic Energy Agency (IAEA) is another sign that new sanctions could be on the way.
The IAEA resolution, censuring Iran's secret construction of another uranium enrichment plant, was supported by Russia and China.
This does not mean they will join in a new round of international measures against Iran. But it does mean that Iran cannot count on them for diplomatic support.
And it shows that Russia might not supply Iran with the S-300 anti-missile system that Iran has ordered. That would be a sanction in itself.
(Update 29 November: Iranian TV has reported that Iran intends to build ten more enrichment sites. This is likely to increase the chances of further sanctions. Iran would have to have such sites under IAEA inspection and at least this time it has announced them in advance.)
US President Barack Obama has indicated that he will assess the Iranian position by the end of the year.
If he goes for more sanctions, he will try to get Russia and China on board. If he cannot, he will act with fellow negotiators Britain, France and Germany, plus, he hopes, the whole EU and other players.
Only two things could stop such moves. The first is Iranian compliance with the security demands for it to stop uranium enrichment.
That will not happen, according to Iran's President Mahmoud Ahmadinejad. He has been consistent on this so it is realistic to believe him.
The other is an agreement on a proposal to take Iran's stockpile of low-enriched uranium (LEU) and send it to Russia and France for conversion into fuel rods for use in Iran's small research reactor in Tehran, which produces isotopes for cancer treatment.
Some Iranian leaders see a trick in this, a way for the West to get hold of its uranium, then keep it.
However the head of the IAEA, Mohamed ElBaradei has said that Iran does have a proposal of its own.
He said this week: "My understanding of Iran's position so far is that it is ready to exchange LEU produced in Iran, in two batches, simultaneously upon receipt of an equivalent amount of fuel for its research reactor.
"Pending receipt of the fuel, Iran is ready to place the LEU under IAEA custody and control, but only in Iran."
Mr ElBaradei, who retires from his post next week, also said: "This opportunity should be seized and it would be highly regrettable if it was missed." This is an understatement.
The UN Security Council has approved three rounds of sanctions so far - covering trade in nuclear material, as well as travel and financial restrictions aimed at Iranian organisations and individuals.
If there are to be new sanctions, then the targets will be Iran's oil trade, especially its reliance on imported refined petroleum products, and the buzzword is reinsurance.
Reinsurance is the means by which insurers can protect themselves against losses and the idea would be to stop or dissuade companies from proving such services for trade with Iran.
According to Wilkie, Farr and Gallaher, an international law firm, the intent is this: "The Obama Administration's sanctions could affect most Iranian import and export trade.
"[Its] proposals could ban goods, services, technology, information, or other activities that support the importation or production of refined petroleum by Iran, including refinery construction, modernization, and repair."
Some governments might be satisfied with that for the time being, bearing in mind that there is no evidence of actual nuclear bomb-making activity and Iran's statement that it will not build any such device.
However, Israel is not and will not be convinced.
New sanctions would have to be given time to work or not.
So a military strike on Iran's nuclear sites at some stage might be less likely in the shorter term, but cannot be not ruled out.