* US, UK, France: Time has come for new sanctions
* China says committed to "dual-track" approach on Iran
UNITED NATIONS, March 4 (Reuters) - Russia and China urged Iran on Thursday to accept a U.N. nuclear fuel proposal aimed at easing concerns about its atomic program, while U.S., British and French envoys said it was time for new sanctions.
The statements by the five permanent, veto-wielding U.N. Security Council members highlighted the different views dividing the United States, Britain and France from Russia and China as they struggle to agree on what should be done to persuade Iran to halt its nuclear enrichment program.
Russia and China, which have reluctantly supported three rounds of U.N. sanctions against the Islamic Republic, renewed their calls for diplomacy and dialogue.
"We do believe that there is still a horizon for negotiations," Russian Ambassador Vitaly Churkin told the 15-nation council. He added that the issue should be resolved "through dialogue and interaction with the Iranian side."
He called on Iran accept a U.N. International Atomic Energy Agency proposal that would enable Tehran to secure fresh nuclear fuel for a research reactor in Tehran that provides isotopes for cancer treatment.
Under the plan, Tehran would ship most of its low-enriched uranium to Russia and France so that it could be further enriched and placed into fuel assemblies for the reactor.
After agreeing to it in principle at a meeting in Geneva in October 2009, Tehran balked, saying it would rather buy new fuel rather than send its own uranium stocks abroad. It has made other counterproposals that have also been rejected.
The United States, Britain, France and Germany say the point of the plan was to move most of Iran's uranium -- enough for a single atomic weapon if enriched to very high purity level -- out of the country to buy time for negotiations.
"Successful implementation of this project would be a credible step in restoring trust in the solely peaceful orientation of the Iranian nuclear program and would best meet the humanitarian needs of the Iranian people," Churkin said.
CHINA: IRAN SHOULD BOOST IAEA COOPERATION
China's deputy U.N. ambassador, Liu Zhenmin, echoed Churkin in urging Iran and the Western powers to redouble efforts to find a solution that would secure fuel for Iran's reactor.
He said that was "the key to easing the current tense situation," along with renewed negotiations with Iran.
But Liu urged Iran to improve its cooperation with the IAEA and reiterated Beijing's commitment to the so-called dual track strategy of combining dialogue with the threat of sanctions to persuade Iran to cooperate.
Western diplomats say Russia is probably ready to back new sanctions, albeit weak ones. But they have doubts about China.
U.S. Ambassador Susan Rice told the council it had to do the right thing and consider "further steps" -- a diplomatic code word for sanctions -- against Tehran for ignoring five council resolutions demanding that it halt enrichment.
"In light of Iran's continued non-compliance with its obligations, this council must consider further measures to hold the government of Iran accountable," Rice said.
The envoys of Britain and France joined Rice in calling for new sanctions. Without naming specific countries, British Ambassador Mark Lyall Grant hinted that new sanctions would help avert military action by Israel, which has made clear that it considers Iran's nuclear program an existential threat.
"Further measures would demonstrate that the international community is united behind a diplomatic resolution to Iran's nuclear issue, and stave off any pre-emptive moves by others to resolve this issue by other means," he said.
The United States, Britain, France and Germany have circulated to Russia and China a revised proposal for a fourth round of sanctions that would expand a U.N. blacklist to include Iran's central bank and other firms and individuals, including some tied to the Islamic Revolutionary Guard Corps.
Western diplomats say the six hope to have a conference call soon to discuss the proposal. Russia's initial reaction has been negative, but China's view remains unclear, they say. (Additional reporting by Edith Honan)
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