Diplomatic efforts between Iran and world powers are taking place in the Austrian capital, with the Director General of the International Atomic Energy Agency (IAEA) is due to visit Tehran on Thursday.

Diplomatic efforts between Iran and world powers are taking place in the Austrian capital, with the Director General of the International Atomic Energy Agency (IAEA) is due to visit Tehran on Thursday.

Diplomatic source said that foreign ministers of France and China are to arrive in Vienna, AFP reported.

The source said that France’s Laurent Fabius and China’s Wang Yi are to hold talks with their US and Iranian counterparts, John Kerry and Mohammad Javad Zarif.

Kerry and Zarif held one-on-one talks on Wednesday. Zarif said the talks were making progress and would continue to do so, Reuters reported.

Meanwhile, Iran’s official news agency, IRNA, reported that the IAEA Chief Yukiya Amano will arrive in Tehran on Thursday to meet President Hasan Rouhani and other senior Iranian officials.

The Vienna-based IAEA said that the visit aims to expedite settlement of all key issues relating to Iran's nuclear program.

“Cooperation between Iran and the IAEA within the frameworks of Joint plan of action will be the main axis of his meetings with Iranian officials,” IRNA said.

For its part, the UN atomic watchdog confirmed its chief was heading to Tehran and that Amano would meet Rouhani.

Iran and world powers are seeking to clinch a final deal on the Islamic Republic’s nuclear program. On Wednesday Iran and the P5+1 extended their deadline until July 7 to agree a deal in talks in Vienna.