"In that short period of time that is left, we hope that we can reach a positive result," said Zarif, speaking through a translator at a news conference on Friday with his Russian counterpart Sergei Lavrov.

Iran and global powers are working to strike a comprehensive agreement by a Nov. 24 deadline, under which Iran would curb its nuclear activities in exchange for an easing of economic sanctions that have crippled its economy.

The talks include the United States, Britain, Russia, China, Germany and France together with Iran, a format known as the 6 +1.

Russian Foreign Minister Sergei Lavrov said Moscow advocated a solution that would acknowledge Iran's right to peaceful nuclear activity.

"We expect that the continuing 6+1 talks will allow the conclusion of such a resolution," he said.

Moscow has helped to bridge differences between Iran and other world powers over Tehran's nuclear activities, which the West fears could be a front to develop nuclear weapons. Iran says it needs nuclear power to generate electricity.

Earlier this month, Russia and Iran announced a big oil-for-food deal, highlighting the problems both countries face in overcoming Western sanctions. Tehran's economy has been struggling for years, while Russia's has been hit by sanctions against its finance, oil and defence sectors over the Ukraine crisis.

Few details were disclosed, but sources told Reuters in January that the two sides were negotiating a deal worth $1.5 billion a month that would enable Iran to lift oil exports substantially,

Western diplomats say there has been little or no narrowing of differences on the issue of Iran's capacity to enrich uranium, an activity that can have both civilian and military uses.