The Russian diplomat said on his Twitter account that "the meeting of Joint Commission of # JCPOA is postponed until late evening."
Ulyanov further said that "informal consultations in various formats were conducted today."
A meeting of the JCPOA Joint Commission will be held on Wednesday with the participation of Iran and the P4+1 (China, France, Germany, Russia, UK) in the Grand Hotel in the Austrian capital.
It was announced before the meeting that the delegations would return to their respective capitals for consultations after today's meeting.
Araghchi said about today's meeting on Monday that he was not sure the ongoing fifth round of the Vienna talks will be the final negotiations despite intense efforts to reach a conclusion.
Reuters reported after today's meeting that Iran's talks with the remaining parties to the nuclear deal were adjourned for a week to Thursday, June 10.
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