He made the remarks before a final day of negotiations after weeks of a fourth round of negotiations with the US and the world powers who are part of the 2015 nuclear deal.
Aragchi said that the parties would need to return to their capitals to receive final instructions toward returning for a potential final round of negotiations to start the middle of next week.
He said, "Good and salient progress has been made in the last two weeks and a few key issues remain that need further investigation and decision-making in the capitals, he said, adding, “We hope that this will happen in the next few days, so that we can conclude on those issues when we come to the next round of talks.”
In addition, Aragchi pointed to the expert-level meetings held over the past two weeks saying, “The situation was very tense. We held various meetings at all levels bilaterally and multilaterally between different delegations at the expert level. During these discussions, we tried to conclude, resolve, or reduce differences on issues of disagreement.”
One issue that has not been addressed was whether enough progress has been made that Supreme Leader Ayatollah Ali Khamenei will extend the May 21 deadline for a deal.
According to that deadline, set by Iran's parliament, absent a deal, all cooperation with the IAEA international inspectors would cease.
Given the progress, it was expected that Tehran would figure out some formula for extending that deadline again for some temporary period.
Israel mostly opposes the US's return to the 2015 nuclear deal, but returning has been a goal of the Biden administration.
Even if a "deal" is reached before June 18, it will still be months before Washington removes its sanctions and Tehran wraps up and ends its nuclear violations due to technical issues like needing to ship enriched uranium out of the country.
No negotiators have shared how Iran will be able to roll back its progress in the area of advanced centrifuges.
Another major issue has been how the US might remove sanctions which the Trump administration labelled as human rights related, but which might really be nuclear-related.
Any deal could have an impact on the June 18 election, though Iran's Guardian Council is reportedly positioned to disqualify any candidates who might challenge the hardliner camp.