"Anyway we are continuing our negotiations in the framework of procedures predicted by the Additional Protocol. There isn't and hasn't been any agreement yet," said Araghchi.

"One of the questions we are discussing is how the Additional Protocol should be implemented," he said.

Also he said that how to implement the additional protocol is among the differences between Iran and the six world powers – known as the P5+1.

Speaking before a meeting between foreign ministers of Iran and the United States, Araqchi said, 'there are issues that we are still seeking to find solutions for them and hope that today's meeting will help find solutions.'

Araqchi and his Foreign Ministry colleague Majid Takht-e Ravanchi have held five rounds of talks with top-ranking EU and US officials over the past month on drafting a comprehensive nuclear deal that Iran and the P5+1 hope to reach by a self-imposed June 30 deadline.

Helga Schmid, the deputy EU foreign policy chief, will also attend today's meeting between Zarif and Kerry to represent other members of the P5+1.

Araqchi expressed hope that the two sides will come to agreement on issues over which there are still differences.

The head of the UN's atomic watchdog Yukiya Amano told AFP in an interview this week that if Iran signs a nuclear deal with world powers it will have to accept inspections of its military sites.

Iranian Foreign Minister Mohammad Javad Zarif and his US counterpart John Kerry started reviewing the procedure of drafting the final nuclear agreement in Geneva on Saturday.