Expert-level talks between Iran and world powers aimed at clearing the path toward a nuclear deal will be held Wednesday and Thursday in Vienna, a top Iranian official said.

Iran and the P5+1 group of nations (Britain, China, France, Russia, the United States plus Germany) are seeking a comprehensive agreement over Tehran's nuclear programme by a November 24 deadline.

However the talks have been hit by disputes over what limits should be placed on Iran's atomic activities, particularly its enrichment of uranium, and on the process of lifting US, UN and European sanctions.

"Negotiations between experts from Iran and the P5+1 will be held Wednesday and Thursday in Vienna," Iranian negotiator and deputy foreign minister Abbas Araqchi was quoted as saying by the official IRNA news agency.

The date of the next meeting between the Iranian delegation, the United States and EU foreign policy chief Catherine Ashton, who is shepherding the negotiations, will be announced later, according to Araqchi.

The deal being sought, after more than a decade of rising tensions, is meant to ease concerns that Iran might be able to develop nuclear weapons under the guise of its civilian energy programme.

To do this, the P5+1 wants Iran to scale down dramatically the scope of its atomic activities, offering in return relief from painful sanctions, but Iran is resisting this.

Iran denies seeking to build the atomic bomb.

In months of discussions since an interim agreement struck last November took effect in January, some progress has been made.

This includes possible changes in the design of an unfinished reactor at Arak so that it produces less weapons-grade plutonium, enhanced UN inspections, and alterations to Iran's fortified Fordo facility.

Many analysts believe that the November deadline may be extended, as happened with an earlier target date of July 20, maybe locking in measures related to Arak and Fordo.