Speaking to the press from his balcony room at the Vienna-based Palais Coburg, Zarif said more work was needed on Monday to close a deal.
Asked specifically if there would be an extension, the Iranian minister replied there would be 'no extension.'
Iranian and E3 plus 3 diplomats are working around the clock to nail down an agreement, finally bringing to an end the 12-year nuclear negotiation process, IRNA reports.