Six world powers failed to reach an accord despite "substantive progress" on a UN resolution to punish Iran for its nuclear activities, the French Foreign Ministry said after closed-door talks in Paris on Tuesday. The five permanent UN Security Council members plus Germany remained split over key questions of visa bans and asset freezes for Iranians linked to nuclear development, which Russia is resisting, a top European diplomat said. After months of diplomatic wrangling, the United States and France had expressed hope that Tuesday's talks would produce a resolution imposing sanctions on Iran for defying UN demands to stop uranium enrichment. The process can produce material for atomic warheads as well as electricity. "We made substantive progress on the scope of the sanctions targeting proliferation-sensitive activities. There remain several outstanding issues, upon which we will reflect over the coming days," the French Foreign Ministry said in a statement late Tuesday night. "We are now close to a conclusion of this process."