Nuclear talks extended seven months: Kerry

ROUGH CUT (NO REPORTER NARRATION)

U.S. Secretary of State John Kerry says nuclear talks in Vienna have made "real and substantial progress" even though Iran and six powers failed for a second time this year on Monday (November 24) to resolve their 12-year dispute over Tehran's nuclear ambitions.

Officials gave themselves seven more months to overcome the deadlock that has prevented them from clinching an historic deal.

"We are certainly not going to sit at the negotiating table forever -- absent, measurable progress. But given how far we have come over the past year, and particularly in the last few days, this is certainly not the time to get up and walk away," Kerry said in a Vienna news conference on Monday.

Western officials said they were aiming to secure an agreement on the substance of a final accord by March but that more time would be needed to reach a consensus on the all-important technical details.

A report by the International Atomic Energy Ag