The diplomat said that most of the six powers were agreed on their demands — with just France demanding stricter terms.

Earlier Saturday, French Foreign Minister Laurent Fabius said Tehran was resisting demands that it suspend work on a plutonium-producing reactor and downgrade its stockpile of higher-enriched uranium to a level that cannot quickly be turned into the core of an atomic bomb.

Fabius’ remarks to France-Inter radio were the first to provide some specifics on the obstacles at the Geneva talks, now in their third day. He spoke by telephone from Geneva, where he, US Secretary of State John Kerry, Russian Foreign Minister Sergey Lavrov and counterparts from Britain, and Germany negotiating with Iran consulted on how to resolve the obstacles at the talks.