By Lindsay Beck
TEHRAN (Reuters) - Iran said on Tuesday a Russian proposal aimed at resolving its nuclear standoff with the West lacked detail and could neither be accepted nor rejected, the semi-official Fars news agency reported.
It was the first time Iran acknowledged receiving the proposal for it to enter a joint-venture to enrich uranium in Russia. The plan is aimed at easing international concerns that Tehran is trying to build a nuclear arsenal.
If enrichment for Iran is carried out in Russia, the European Union argues, the international community can be sure only low-grade uranium suitable for power stations is produced and not highly-enriched uranium for nuclear bombs.
Iran says it only wants to enrich uranium to a low-grade for generating electricity, but in two years of tortuous talks with the EU has insisted it wants to do it itself.
But European diplomats and analysts say Iran has been careful not to reject the Russian proposal outright -- a move which could see its case referred to the U.N. Security Council for possible sanctions.
An "informed source who declined to be named", told Fars news agency: "This proposal could not be seen as a plan as it lacks details."
The Russian Foreign Ministry said on Saturday it had submitted a formal offer to Iran that would allow it to establish a civilian nuclear programme but transfer enrichment to Russia.
But the Iranian source told Fars: "The whole letter is on one page, one and a half lines of which concern making an Iranian-Russian joint venture on Russian soil for enriching uranium.
"There are no details in that proposal and its mechanisms and limits are not defined. Therefore, we cannot express opinions on it," the source said.
Iranian nuclear negotiators met counterparts from the EU trio of Britain, Germany and France in Vienna last week for the first face-to-face talks for several months. Both sides agreed to meet again in January.