Iranian Foreign Minister Mohammad Javad Zarif smiles during a news conference after nuclear talks at the United Nations European headquarters in Geneva. Picture: Denis Balibouse

BRUSSELS - Iran and six world powers have extended expert-level talks in Geneva on the implementation of a landmark deal obliging Tehran to curb its nuclear programme for at least one additional day, diplomats said on Friday.

A round of discussions on the deal started on Thursday in Geneva and was scheduled to last through Friday.

The seven countries need to decide when the agreement goes into effect and to work out technical aspects of how Iran will suspend its most sensitive nuclear work.

In return for nuclear concessions, Western governments will ease some economic sanctions, but they have yet to agree how much prior verification they will get to be assured that Iran is meeting its obligations.

Iran rejects Western fears that its nuclear work has any military intentions and says it needs nuclear power for electricity generation and medical research.

The Nov. 24 agreement is meant to give the six powers - the United States, Russia, China, France, Britain and Germany - time to negotiate a final settlement with Iran that could put an end to the decade-old standoff and ease worries over a new war in the Middle East.