Framework for Iran deal 'very likely'

The US Secretary of State John Kerry is back in Switzerland for the latest round of diplomatic negotiations over limiting Iran's nuclear program.

Many regional players have recently weighed in on the prospect of a deal, including a senior member of the Saudi royal family who voiced concerns to the BBC.

However, former White House Coordinator for Arms Control Gary Samore, now at Harvard's Kennedy School of Government, says a deal is the best option for managing the problem under the circumstances.

"Any of the alternatives, going back to sanctions or using military force, are much less certain of success and carry their own risks," Samore told the BBC's Katty Kay.