Iran said Thursday it needs Moscow to clarify what it called "ambiguities" in a proposal that Iran enrich uranium in Russian territory.

Iran said it was considering the European- and U.S-backed proposal, a relatively conciliatory stance after weeks of outright rejection of moving enrichment abroad.

The proposal aims to ensure that Iran cannot build nuclear weapons. Uranium enrichment can produce fuel for a nuclear reactor or material for a bomb. Under the proposal, Iran would generate fuel for its reactors in Russia.

"The Russian proposal about Iran's nuclear activities has problems and ambiguities that need to be clarified in further talks," Iran's top nuclear negotiator, Ali Larijani, told Russian Security Council head Igor Ivanov, in a telephone conversation Thursday, state-run television reported. Larijani did not specify the problems.

His remarks may result from an attempt by Iran — which is under intensified pressure to accept the deal — to gain time without directly rejecting a proposal from Moscow, a longtime ally that is helping build Iran's first nuclear reactor.

Iran at first denied receiving the enrichment proposal, but confirmed on Wednesday that it was considering it. The enrichment proposal was made public weeks ago and formally presented to Tehran last week.

Larijani and Ivanov agreed that the deputy head of the Russian Security Council will visit Tehran soon to discuss the proposal, the report said.

Hard-line Iranian politicians have denounced the Russian proposal, but European negotiators are hoping an enrichment compromise can bring a breakthrough in deadlocked negotiations aimed at ensuring Iran cannot produce nuclear weapons. Talks between Iran and the Europeans — Britain, France and Germany — resumed earlier this month, making little progress, and are to continue in January.

Iran says its nuclear program is intended only for electricity generation and denies U.S. charges it is trying to develop nuclear weapons.

Javad Vaidi, a top Iranian nuclear negotiator, said Wednesday that Russia's proposal was to "set up a joint Iranian-Russian company to enrich uranium in Russian territory." He suggested, however, that Tehran would not scrap its uranium enrichment program at home, saying the Russian proposal would not remove Iran's rights under the Nuclear Non-Proliferation Treaty to carry out enrichment.

"Whatever meaning the Russian proposal may have, it won't mean ... denying Iran its treaty rights," he said.

The nuclear program is a source of national pride in Iran, and any government that abandons enrichment likely would lose public support.

Meanwhile, Washington is pushing for Tehran to be brought before the United Nations Security Council, where it could face economic sanctions over the dispute.

Russia and China, which have vetoes on the council, oppose referral and the West has stopped short of forcing the matter.