The fourth round of high-level talks on Iran’s nuclear program kicked off in the Kazakh city of Almaty on Tuesday to discuss Tehran’s ongoing effort to enrich uranium. It's not clear if the talks will conclude Tuesday night or stretch into a second day. Negotiators from the six world powers – United States, Russia, China, Britain, France and Germany – will offer Iran some small new relief from harsh international sanctions to entice Tehran into stopping enriching uranium close to a weapons-grade level. The Iranian delegation is headed by the country’s National Security Council Secretary Saeed Jalili, while Russia is represented by Sergei Ryabkov and the US by Under Secretary for Political Affairs Wendy Sherman. The meeting with also be attended by EU’s High Representative Catherine Ashton. The western nations are pressing Iran to give up the effort, since uranium, enriched to 20%, could be used by Iran to manufacture a nuclear bomb. But Tehran claims that its program is exclusively peaceful in character and that it needs uranium as fuel for its research reactor. The talks have resumed after an eight-month hiatus and are to last two days. The most recent negotiations between P5+1 and Tehran ran off in June 2012 in Moscow and lasted for two days. This time, the talks can last even longer since diplomats claimed they were intent on going the extra mile.