Talks in Vienna between world powers and Iran have ended amid mixed messages.
The two days of meetings were aimed at paving the way towards a comprehensive deal to curtail Tehran’s enrichment of uranium.
A senior US administration official is quoted as saying it’s unclear if the six powers and Iran will succeed in overcoming their differences.
Negotiators remain positive.
“A lot of intensive work will be required to overcome the differences which naturally still exist at this stage in the process. We will now move to the next stage of the negotiations in which we will aim to bridge the gaps between all the key areas, and work on the concrete elements of a possible comprehensive agreement,” said Catherine Ashton, High Representative of the European Union for Foreign Affairs and Security policy.
Iran’s negotiator Foreign Minister Mohammad Zarif will meet with representatives from the six world powers next month.
In Tehran the supreme leader Ayatollah Khamenei backed the ongoing talks but warned Iran will never give up its nuclear programme.
“All should know that negotiations will not stop of slow down any of Iran’s activities in nuclear research and development,” he is reported as telling nuclear scientists meeting in Tehran.
Iran denies suspicions it is after nuclear weapons.