Despite progress, Iran nuclear talks hit impasse on details

(Reuters) – Major powers and Iran were closer to a preliminary accord on Tehran’s nuclear program as marathon talks ran into Wednesday, but were stuck over key details such as lifting U.N. sanctions and Iran’s future atomic research.

After missing a self-imposed March 31 deadline for a deal, the negotiators ended talks in the Swiss city of Lausanne in the early morning hours with an air of chaos, disunity and cacophony as delegations scrambled to get contradictory viewpoints across.

The six powers – the United States, Britain, France, Germany, Russia and China – aim to stop Iran from gaining the capacity to develop a nuclear bomb in exchange for easing international sanctions crippling its economy.

Iran says its nuclear program is peaceful.