Iran and six world powers have begun a second day of talks in Geneva, Switzerland.
Reports quote officials on both sides as saying the first day of talks on December 6 was "constructive."
But no breakthroughs were reported in connection with United Nations Security Council demands for Iran to halt uranium enrichment activities that could be directed toward the development of a nuclear weapon.
Iran denies any intention to make such a weapon.
On December 7 in Tehran, an Iranian Foreign Ministry spokesman, Ramin Mehmanparast, called on world powers to show "courage" and recognize the country's "right" to a nuclear fuel cycle.
The talks bring together Supreme National Security Council Secretary Saeed Jalili, Iran's top nuclear negotiator, and representatives from Britain, China, France, Germany, Russia, and the United States.
The Geneva talks mark the first such meeting between Iran and the six powers in more than one year.
compiled from agency reports