Tehran, YJC. Iran and the sextet representatives started their official meeting in EU Headquarters in Geneva on Sunday.
Deputy foreign ministers of Iran and Group 5+1 (US, Britain, France, Russia, China, and Germany) are holding the meeting after four days of intense talks.
Iranian and US negotiators have so far met and discussed at different levels of ministers, deputies, and experts during the past four years.
US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif met 3 times on Wednesday in Geneva, Switzerland.
They also met for the fourth time on Friday. The discussions aim to speed up process of nuclear negotiations between Iran and Group 5+1.
After negotiations with Kerry, Zarif left Geneva for Berlin on Wednesday to talk with his German counterpart Frank Walter Steinmeier.
Zarif also met with the High Representative of the European Union for Foreign Affairs Federica Mogherini in Brussels. He then left for Paris to talk with French Foreign Minister Laurant Fabius.
After France, Zarif returned to Geneva to monitor discussions between his deputies and experts with the US delegation. In Switzerland, he also talked on the phone with his British counterpart Philip Hammond and then left for Tehran.
On Saturday, Zarif's deputies Abbas Araqchi and Majid Takht Ravanchi, after 4 days of talks with the US delegation, met with Mogherini's Deputy Helga Schmidt as well as Russian Deputy Foreign Minister Sergei Ryabkov.
The 5-day Geneva discussions are the second round of negotiations after the extension of talks and the first round of nuclear talks in 2015.
Iran, Group 5+1 talks have been extended until July 1st, 2015, so that the two sides can reach a general agreement in the first 4 months and work out details of the agreement in the next three months.