Iranian President Hassan Rohani has said his government will defend the Islamic Republic's nuclear rights and work to end crippling international sanctions.
The moderate Rohani has been criticized by hard-liners for making too many concessions to the West in return for little.
Under an interim deal in November, Iran agreed to cap its nuclear activities in return for an easing of sanctions by the West.
The West accuses Iran of using its nuclear program to secretly develop nuclear weapons, a charge Tehran denies.
The next high-level talks aimed at finalizing a deal will be held later this month.
Another round of expert-level nuclear talks between Iran and world powers is scheduled for June 4 in Vienna.
Russia's United Nations Ambassador Vitaly Churkin said June 3 that the talks "have been going well but not without problems."
Based on reporting by AP and AFP