Delicate talks between Iran and world powers on how to implement a landmark nuclear deal were to resume in Geneva Thursday, as France’s foreign minister cast doubt on their chance of success.

Delicate talks between Iran and world powers on how to implement a landmark nuclear deal were to resume in Geneva Thursday, as France's foreign minister cast doubt on their chance of success.

The technical talks were set to begin at 3:00 pm (1400 GMT) in the Swiss city, Iran's deputy foreign minister and lead negotiator Abbas Araqchi, who is not personally taking part in the expert-level negotiations, told Iranian state television.

Experts held four days of talks in Vienna last week, but the Iranians walked out after Washington expanded its sanctions blacklist against Tehran.

Tehran was prepared to continue the talks after EU foreign policy chief Catherine Ashton "made the assurance that the world powers, particularly the United States, will continue the talks in goodwill... and that they are serious about implementing the deal," Araqchi told Iran's state broadcaster on Wednesday.

However, French Foreign Minister Laurent Fabius, one of the key players in the
negotiations with Tehran, cast doubt Thursday on the chances of a final nuclear
deal.

"It is unclear if the Iranians will accept to definitively abandon any capacity of getting a weapon or only agree to interrupt the nuclear program," he told the Wall Street Journal.

The fresh round of negotiations, being held at an undisclosed venue in Geneva, is scheduled to last through Friday, but Araqchi said talks could be extended into the weekend.