LAUSANNE, Switzerland (Reuters) - With a deadline hours away, Iran and six world powers stepped up the pace on Tuesday in negotiations over a preliminary deal on curbing Tehran's nuclear programme 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.