Iranian Foreign Minister Mohammad Javad Zarif and EU High Representative for Foreign Affairs and Security Policy Catherine Ashton, who leads the group of six countries, wrapped up their fourth meeting in three days in the Swiss city of Geneva on Friday. Iran and the five permanent members of the UN Security Council - the US, France, Britain, Russia and China - plus Germany kicked off their latest round of talks on Wednesday. The two sides are working to hammer out an interim deal to pave the ground for the final resolution of the West’s decade-old standoff with Iran over its nuclear energy program. The recognition of Iran's entitlement to enrich uranium for peaceful purposes  remains one of the major sticking points in the talks. Iran’s Deputy Foreign Minister for International and Legal Affairs Abbas Araqchi, who is also a member of the Iranian nuclear negotiating team, said on Thursday that Tehran would not accept any deal which does not include the right. On Thursday, Ashton’s chief spokesperson Michael Mann described the ongoing talks between the two sides as very “substantial and detailed.” “It was not your classic bilateral [meeting]. It was a real, meaningful, detailed, substantial negotiation, trying to drill down into the details of the text, trying to narrow the differences that still existed after the last round,” he added. The Iranian team echoed the remarks, saying discussions have already delved into content and details. However, they added that differences remain between the two sides. During the last round of talks in Geneva in early November, a first-step agreement was within reach but the position taken by French Foreign Minister Laurent Fabius in favor of the Israeli regime and a lack of commitment by US Secretary of State John Kerry spoiled the negotiations.