The stage looks set in Vienna for a final deal between Iran and six world powers after more than a year of talks aimed at curtailing Tehran’s nuclear programme in exchange for relief from international sanctions.

US Secretary of State John Kerry says progress is being made ahead of a new target date of July 7. His Iranian counterpart, Mohammad Javad Zarif, has gone further, posting a video message on YouTube.

“At this eleventh hour, despite some differences that remain, we have never been closer to a lasting outcome but there is no guarantee,” the Iranian Foreign Minister says in the video.

In another key step, the UN atomic watchdog hopes to swiftly present its findings into past Iranian research suspected of being linked to nuclear weapons development.

“With cooperation from Iran, I think we can issue a report by the end of the year on the assessment of the clarification of the issues related to the possible military dimensions,” International Atomic Energy Agency Director-Ge