EU foreign policy chief says Iran nuclear deal 'very close'

Vienna: A nuclear deal with Iran is "very close" after almost two years of negotiations, the EU's foreign policy chief Federica Mogherini said.

Speaking as she arrived back in Vienna to join down-to-the-wire negotiations, Mogherini told reporters: "The time is now... We are very close."

Global powers -- Britain, China, France, Germany, Russia, and the United States -- have been seeking to hammer out a deal with Iran to curtail its nuclear programme in exchange for an easing of biting sanctions.

After an intense weekend of talks between US Secretary of State John Kerry and his Iranian counterpart, ministers are returning in the hopes of being able to finalise the deal.

"The atmosphere is constructive, positive," Mogherini told reporters as she arrived at the Palais Coburg where the closed-door negotiations are being held. "I see the political will ... now it is a matter of seeing all together if this political will manages to translate into political decisions." "Now is the time to see if all of this matures into a deal," she added.