Iran nuclear talks: Kerry says 'substantial progress' made towards deal, but gaps remain

Diplomats confirm provisional agreement has been reached on Iran's enrichment capacity, but UN sanctions remain possible obstacle as major deadline approaches International negotiations on Iran's nuclear programme have made dramatic strides towards a comprehensive agreement, according to diplomats at the marathon talks, now entering a critical last week before a major deadline. The negotiators are due to gather once more in Lausanne on Wednesday, for a session that is due to last until Sunday, b...