On Friday, Iranian Deputy Foreign Minister Abbas Araqchi said that the foreign ministers of Iran and the P5+1 group of international mediators could move to the UN building in Geneva from Lausanne in case a concluding meeting is necessary.
"Yes, we are ready to urgently organize a meeting but no requests have been made so far," the source said.
Also on Friday, Araqchi said that certain unresolved issues still remained but the negotiators were working toward resolving them.
The West has reservations about Iran's program, accusing the Islamic republic of covertly developing nuclear weapons. Iran has said that the nuclear program was developed to meet the country's growing energy needs.
The participants of the talks should produce a political framework agreement by the end of March, while a comprehensive deal to ensure the peaceful nature of Tehran's nuclear program is expected by July.