Negotiators prepared on Saturday for European-Iranian talks billed by six world powers as the last chance for Iran to avoid UN sanctions over its nuclear defiance. Javier Solana, the European Union's foreign policy chief, was to meet with senior Iranian nuclear negotiator Ali Larijani. The talks were focusing on whether there is common ground to start negotiations between Teheran and the six countries offering rewards if the Islamic republic gives up uranium enrichment - and punishment if it does not. The exact time and venue of the talks were not made public, and Iran's chief delegate to the International Atomic Energy Agency, Ali Ashgar Soltanieh, suggested they were still not set by early Saturday. But he indicated they would not begin before the afternoon. The five permanent members of the UN Security Council and Germany agreed on a package of economic and political rewards in June to be offered to Tehran, if it stops enrichment before the start of negotiations, meant to achieve a long-term enrichment moratorium. But the six-nation alliance also warned of punishments, including UN sanctions, if Tehran does not halt enrichment - something Iran refused to do by an Aug. 31 deadline set by the Security Council. On Friday, US Undersecretary of State Nicholas Burns said Washington expected the Security Council to start discussing a draft on sanctions as early as next week unless Teheran does a last-minute turn and agrees to freeze enrichment, a possible pathway to nuclear arms. Russia and China urged continued patience and said sanctions should not be rashly imposed. Burns additionally dismissed suggestions of cracks in coalition pushing Iran to give up enrichment. He spoke in Berlin, a day after those countries ended confidential discussions on Iran in the German capital. Outlining the US view of the timetable on Iran in the coming weeks, Burns said the six nations would consult further by phone on Monday and hoped to present a unified approach on sanctions to their foreign ministers by the time the UN General Assembly opens Tuesday. "It's fair to say we have ... a lot more work to do," he said, adding: "The American view is that following these discussions on Monday and perhaps some others early next week, we should move this to the Security Council and draft a resolution" on sanctions.