The chief inspector of the United Nations nuclear watchdog arrived Monday in Tehran to hold talks with officials of the Iranian Atomic Organization to Tehran, the ISNA news agency reported.
The International Atomic Energy Agency's (IAEA's) chief inspector, Olli Heinonen, is in Tehran to follow up on last week's negotiations with the head of the Iranian Atomic Organization, Gholam-Reza Aqazadeh, ISNA reported.
Tehran termed the two-day talks last week as "constructive" but refrained from saying whether they also opened up perspectives for a breakthrough in the nuclear dispute.
The Iran-IAEA talks are chiefly technical and do not deal with political issues, such as whether Iran would suspend uranium enrichment in return for political and economic incentives.
The United Nations has already imposed three sets of sanctions aimed at forcing Tehran to give up uranium enrichment
Tehran has said its nuclear programme is designed for peaceful purposes, but the United States and other Western nations want further guarantees that the Islamic state is not pursuing a secret weapons programme.
A package of incentives drawn up by the five permanent members of the UN Security Council plus Germany requires Iran to suspend enrichment in return for political and economic benefits.
Iran has ruled out the possibility of accepting Western demands that it bring its enrichment programme to a halt.

Shares fell 2.1 per cent Friday on the Seoul stock exchange on general recession fears. South Korea's won dropped against the dollar.
When the Spirit rover landed on Mars five years ago, no one expected it or its sister rover Opportunity to make it to their first birthdays, let alone their fifth.
Amelie Mauresmo fell victim to a leg injury after less than half an hour on court Friday to hand over a 4-0 victory which put French compatriot Marion Bartoli into the final of the Brisbane International.
Mumbai-based movie Slumdog Millionaire won five prizes Thursday night at the Critics Choice Awards, cementing its position as a surprise favourite just as the Oscar season moves into high gear.
After the Taipei Zoo received two giant pandas from China, another Taiwan zoo said Friday it is seeking to receive a pair of pandas from China.