The discussions are the first since Iran and the P5-plus-1 (Russia, the United States, Britain, China, France and Germany) adjourned Feb. 20, Iran's Tasnim news agency reported.
When the February talks adjourned, Iranian Foreign Minister Mohammad Javad Zarif, the republic's top nuclear negotiator, said both sides had developed a framework for comprehensive negotiations to reach a final agreement.
The two sides are gearing up for a meeting of political directors March 17 after the technical experts meet.
The discussions are the result of a landmark interim deal reached by Iran and the six powers in November in Geneva, Switzerland. Based on the Geneva interim deal, the world powers agreed to suspend some non-essential sanctions and not impose new nuclear-related bans in return for Tehran's decision to suspend its 20 percent uranium enrichment for six months, during which negotiators will draw up a comprehensive nuclear deal which will lead to a lifting of the whole sanctions on Iran.