"As you know we have never been so close to a deal, yet some critical points are not solved," Mogherini said.
“In the last weeks we’ve made substantial progress so the work of the last weeks had been very positive. But still there are some points on which we have to work very hard to find solutions that are good… that can guarantee that Iran has no nuclear weapons, but still can develop civil nuclear program," Mogherini added.
"If we have common understanding… than we can have the deal that can be solid… Having a good deal would be obviously very important for us," EU foreign policy chief said.
Since November 2013, Tehran and P5+1 group comprising Russia, the United States, China, the United Kingdom, France and Germany have been holding talks aimed at reaching a comprehensive agreement that will ensure peaceful nature of Tehran’s nuclear activities.
The most recent round of negotiations on the Iranian nuclear deal between P5+1 and Tehran started in Lausanne on Thursday and will last until March 29.
On Saturday Mogherini arrived in Lausanne to join the talks.
The final agreement on Iran's nuclear activities is expected to be reached by July 2015. The political framework for the deal is to be ready by the end of March.
