Three days of multinational diplomatic discussions in Geneva concerning Iran's nuclear program have ended without an agreement Sunday, CNN reported.
"A lot of concrete progress has been achieved, but some differences remain," EU foreign policy chief Catherine Ashton said.
Iranian Foreign Minister Javad Zarif told CNN early Sunday that he's optimistic "that we will be able to reach an agreement when we meet again."
"I think we are all on the same wavelength, and that's important," Zarif told CNN.
This is breaking news; updates will be added.