EU foreign ministers, meeting in Brussels Monday, are to agree to halt the import and export of nuclear-related goods, freeze the assets of those linked to the programme and impose a travel ban on some individuals.
"The EU is really determined to interpret the resolution in a very strict way. We want to send a clear message to Iran," an EU diplomat said, on condition of anonymity.
According to a draft of the conclusions they are to adopt Monday, drawn up in advance by ambassadors, the ministers will call "on all countries to implement the measures in full and without delay."
Officials say the EU has imposed a "de-facto" arms embargo on Iran for the last decade and the ministers will only recall "EU policy not to sell arms to Iran", if their draft text remains in the form seen by AFP Friday.
One EU official said their refusal to formalise the ban was "to keep some ammunition for later on."
The UN Security Council passed resolution 1737 on December 23 imposing sanctions on Iran because it has repeatedly refused to fully cooperate with the UN’s atomic energy watchdog or suspend uranium enrichment.
Highly-enriched uranium can be used to build an atom bomb and the West fears that the Islamic republic could be trying to develop such a weapon under the guise of a civilian nuclear programme.
Iran maintains that it is only exercising its right as a signatory of the nuclear Non-Proliferation Treaty (NPT) to develop nuclear technology to meet its energy needs.
The ministers are expected to prepare a list of officials subject to visa bans, which could differ from the list annexed to the UN resolution as it might include Iranians studying proliferation-sensitive subjects in Europe.
Overall, they will "deplore Iran’s failure to take the steps repeatedly required" by the International Atomic Energy Agency (IAEA) and the UN Security Council.
A senior EU diplomat underlined that the 27-bloc has not withdrawn its offer from last year of a package of political and economic incentives to encourage Tehran to give up the sensitive enrichment activities.
"We have always said that the door remains open, but somebody has to want to step through it," he said.