MOSCOW, March 1 (Xinhuanet) -- Russia and Iran ended their negotiations on uranium enrichment in Moscow on Wednesday without any breakthrough.

    "The conversation was constructive and earnest, but quite a few questions remain unresolved," Russian Deputy Foreign Minister Sergei Kislyak told reporters after the talks ended.

    Speaking after the talks with Russian Security Council Secretary Igor Ivanov, Iran's chief nuclear negotiator Ali Larijani said Iran and Russia have reached "a general agreement" on the issue but more work is needed.

    "It is necessary to study the issue in detail, which will take time," Larijani said.

    The Interfax news agency quoted a source in the Iranian delegation as saying Iranian officials hope to have more talks before flying home at noon Thursday.

    The Russian plan, backed by Western countries, is seen as a crucial attempt to resolve the dispute over Iran's nuclear program before the March 6 meeting of the International Atomic Energy Agency (IAEA), which reports say could start a process leading to UN punishment against Iran.

    Russia and Iran underlined the importance of talks and consultations for the resolution of the Iranian nuclear issue by diplomatic methods and within the framework of the IAEA, Interfax reported citing a joint statement.

    After the previous two rounds of talks last week in Moscow and Tehran, Iran said on Sunday it had agreed in principle with Russiaon setting up a uranium enrichment joint venture.

    But Larijani said Iran does not intend to give up the right to enrich uranium by itself even if it reaches a deal with Russia on a joint venture. Enditem