"Prospect of a deal in #ViennaTalks remains unclear due to Washington's delay in making a political decision", Ali Shamkhanit tweeted on Monday.
Shamkhani also noted that "Iranian negotiators' priority is to resolve the remaining issues that are considered as our red lines."
The top Iranian security official further said that in order to achieve an agreement quickly in Vienna new initiatives from all parties is is needed.
Earlier on Monday, he tweeted that the positive and negative actions of the countries participating in the Vienna talks are aimed at securing interests and this is understandable,"
"Securing the interests of the Iranian nation is the only factor influencing Iran's interaction with the P4+1 group," he also said.
Evaluation of new effective components in the talks and the adoption of negotiation initiatives are on the agenda to accelerate achieving a result, Shamkhani noted.
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