MOSCOW/BRUSSELS/TEHRAN – Russia regrets that Iran has apparently rejected a UN-brokered nuclear fuel exchange deal to ease the standoff over its atomic programme, Foreign Minister Sergei Lavrov said on Friday. "We regret that Iran – as far as we can see – does not consider it possible to agree to the formula that it was offered," Lavrov told a news conference. Under the plan, Iran would hand over most of its stocks of low-enriched uranium in return for the supply by France and Russia of nuclear fuel enriched to the higher level required for a Tehran research reactor. "Our aim is clear. We want that the international community does not have any doubt on the peaceful nature of the Iranian nuclear programme," added Lavrov. He noted that the UN Security Council had the capacity to "study further measures on Iran" but once again did not come out explicitly in support of further UN sanctions against the country. "Acting with a logic of punishing Iran... is not a sober approach," he said. However, Iranian Foreign Minister Manouchehr Mottaki insisted Iran did not reject "the principle" of the nuclear fuel deal. Moscow's capacity to provide technical help for the Iranian nuclear drive is seen by some analysts as giving it an unmatched power of leverage in Tehran. Russia is building Iran's first nuclear power plant in the southern city of Bushehr and the facility is due to finally come on line this year. Meanwhile, European Union (EU) foreign ministers are to discuss how the bloc can put more pressure on Iran to end its controversial nuclear programme at a meeting in Brussels on Monday. The EU is keen to bring its influence to bear on Iran in the nuclear dispute, but member states are at odds over the question of whether sanctions would be the best way to do so and whether the bloc should bring in its own measures without United Nations approval. Ministers are therefore expected to debate what kind of sanctions the bloc could impose on Iran if the UN called for more action, but without calling for unilateral EU measures. The debate comes six weeks after EU leaders at a summit in Brussels issued a statement calling on Iran to shut down its controversial uranium-enrichment programme. ' Iran's persistent failure to meet its international obligations and Iran's apparent lack of interest in pursuing negotiations require a clear response, including through appropriate measures,' their joint statement said. The EU would be ready to back UN sanctions on the issue, leaders said, ordering their foreign ministers to 'consider options for next steps to this end' at their meeting scheduled for Monday. The EU already has a number of sanctions in place on Iran. They range from asset freezes on banks and key figures linked to the nuclear programme, to embargoes on exports of arms and equipment. In Tehran, students had boycotted end-of-term exams as they continue to show their opposition to the outcome of last year's disputed presidential election. The move comes a month after thousands of students held street demonstrations to protest against President Mahmoud Ahmadinejad's re-election last June. Students have been at the forefront of the protests, which initially saw millions of Iranians taking to the streets to demonstrate against the result of the poll.