Switzerland- With a deadline hours away, Iran and six world powers ramped up the pace on Tuesday in negotiations over a preliminary deal on Tehran's nuclear program, while officials cautioned that any agreement would likely be fragile and incomplete.
For nearly a week, the United States, Britain, France, Germany, Russia and China have been trying to break an impasse in the talks, which are aimed at stopping Iran from gaining the capacity to develop a nuclear bomb in exchange for easing international sanctions that are crippling its economy.
But disagreements on enrichment research and the pace of lifting sanctions threatened to scupper a deal that could end a 12-year standoff between Iran and the West over Tehran's nuclear ambitions and reduce the risk of another Middle East war.
"The two sticking points are the duration and the lifting of sanctions," an Iranian official said. "The two sides are arguing about the content of the text. Generally progress has been made."
Officials played down expectations for the talks in the Swiss city of Lausanne.
For days they have been trying to agree on a brief document of several pages outlining key headline numbers to form the basis of a future agreement. Officials said they hoped to be able to announce something, though one Western diplomat said it would be "incomplete and kick some issues down the road".
Negotiations among the parties on sticking points went into the night and continued on Tuesday. They were expected to run late and possibly into Wednesday. Officials said they were hoping to agree on some kind of declaration, while any actual preliminary understanding that is agreed might remain confidential.
It was also possible they would not agree on anything.