A third round of nuclear talks between experts from Iran and six world powers has started in Geneva.
The talks are aimed at setting a framework to implement last month's landmark nuclear deal.
Two rounds of talks have been held so far since Tehran agreed on November 24 to suspend parts of its disputed nuclear program for six months in return for limited sanctions relief while a longer-term agreement is forged.
Iran's Mehr news agency on December 29 quoted Iran's top nuclear negotiator, Abbas Araqchi, as saying he hoped the deal could be implemented within a month.
Araqchi, however, said the talks are "proceeding slowly, as there are misunderstandings over the interpretation of some elements of the accord."
The first round of talks were interrupted when Iranians walked out after Washington expanded its sanctions blacklist against Tehran.
Based on reporting by AFP, Interfax, and Reuters