By Ramin Mostafavi
TEHRAN (Reuters) - Iran could cancel an accord with Turkey and Brazil to transfer some of its enriched uranium abroad if the U.N. Security Council approves a fresh round of sanctions against it, a member of parliament said on Thursday.
A Russian official meanwhile confirmed that Iran is set to open a long-delayed nuclear reactor built by Russia, a step likely to fan Western fears that the Islamic republic could one day become a nuclear weapons power.
Sergei Kiriyenko, head of Russia's state nuclear corporation Rosatom Corp, told journalists the reactor at the Bushehr plant would begin to operate in August.
Russia is one of the five permanent members of the U.N. Security Council who have approved a draft resolution on a new set of sanctions against Iran that Washington circulated at the United Nations on Tuesday.
Iran could scuttle the deal to part with 1,200 kg of its low-enriched uranium (LEU) if the sanctions resolution is passed, prominent lawmaker Mohammad Reza Bahonar was quoted as saying by Iran's Mehr news agency.
"If (the West) issues a new resolution against Iran, we will not be committed to Tehran's statement and despatching fuel outside Iran will be cancelled," he said.
The draft resolution appeared to brush aside as too little and too late the surprise deal brokered by Brazil and Turkey the day before for Iran to send the LEU -- potential nuclear bomb fuel -- abroad in return for fuel rods to keep a Tehran medical research reactor running.
The first batch would arrive in Turkey within a month.
Such an arrangement was first mooted last October as a way, in Western eyes, to cut Iran's LEU stockpile below the minimum that would be needed for a nuclear weapon -- if enriched to a high fissile purity -- and buy time for more negotiations.
Turkey and Brazil -- both currently on the Security Council -- and Iran have urged a halt to talk of further sanctions because of the deal. But Western critics have described it as only a tactic to avert or delay sanctions.
This is because the amount of LEU Iran would hand over -- the same as that originally negotiated under the aegis of the U.N. nuclear watchdog -- would still leave Iran with enough for one bomb, since it has produced more LEU since then.
RUSSIAN APPEAL TO IRAN
Brazilian President Luiz Inacio Lula da Silva said on Thursday that Iran had shown willingness to negotiate its nuclear program and other countries now needed to do the same.
"Iran, which had been sold to the world as the devil ... sat down at the negotiating table. I want to see the others comply with what they wanted Iran to do," Lula said during a speech to mayors in the capital, Brasilia.
In a possible effort to get Iran to prove it was serious about a pact it backed out of earlier, Russian Foreign Minister Sergei Lavrov urged Tehran on Thursday to send the details to the International Atomic Energy Agency.
Iran has said it will get in touch with the IAEA by May 24.
The new, extended sanctions would target Iranian banks and call for inspection of vessels suspected of carrying cargo related to Iran's nuclear or missile programs.
Lavrov was quoted by Interfax news agency as saying he hoped for a consensus in the Security Council on the fourth sanctions resolution against Iran since 2006, expected to come to a vote next month.
Western diplomats do not expect Brazil, Turkey or Lebanon to support the resolution and are hoping for 10-12 votes in favour in the 15-nation body -- enough to pass the measure.
Iranian officials have dismissed the draft resolution as lacking legitimacy, and rejected international demands to suspend enrichment.
Iran says it is refining uranium only for civilian nuclear energy plants. Western powers suspect Iran wants to "weaponise" enrichment technology because it restricts U.N. nuclear inspections and has stonewalled a U.N. probe into intelligence claims that it has studied ways to make a nuclear warhead.
"The Americans will take their wish to harm the Iranian nation to their graves," President Mahmoud Ahmadinejad was quoted as telling military officials on Thursday by state news agency IRNA.
Washington has spent much diplomatic effort in persuading Russia and China, also a permanent Security Council member, to back sanctions and a tougher line on Tehran.
Both want to maintain trade relations with Iran, a major energy producer. Iran hopes to buy S-300 air defence missiles from Russia but it is not clear yet if Russia will deliver. And some Western diplomats say the deal would be blocked by the new resolution, which prohibits sales of heavy weapons to Tehran.
Moscow says the Bushehr plant is purely civilian and cannot be used for any weapons program as it will come under IAEA supervision. Iran will have to return all spent fuel rods to Russia, a provision meant to stop reprocessing into bomb fuel.
(Additional reporting by Conor Humphries and Dmitry Solovyov in Moscow and Raymond Collitt and Maria Carolina Marcello in Brasilia; Writing by Andrew Hammond and Patrick Worsnip; Editing by Cynthia Osterman )