The European Union’s foreign policy chief, Federica Mogherini, said on Tuesday that a comprehensive agreement on Iran’s nuclear program would benefit all sides.

The European Union's foreign policy chief, Federica Mogherini, said on Tuesday that a comprehensive agreement on Iran’s nuclear program would benefit all sides.

Speaking at Chatham House, a think tank in London, the EU official said that an Iran nuclear deal was “at hand” if the negotiating sides demonstrated political will.

"A good deal is at hand if the parties will keep cooperating as they did so far and if we have enough political will from all sides to agree on a good deal and sell it domestically," Mogherini said, adding “We cannot miss this opportunity.”

Representatives from Iran and the United States started nuclear talks on Sunday in the Swiss city of Geneva. They held three rounds of negotiations in an attempt to narrow the differences.

Speaking to reporters in Geneva on Monday, Iranian Foreign Minister Mohammad Jawad Zarif said negotiators from Iran and the P5+1 countries - Britain, France, China, Russia, and the United States plus Germany – will resume their discussions in the Swiss city next week.

Iran and the six world powers have missed two deadlines so far to reach a nuclear agreement since an interim deal was sealed in November 2013. The two sides have set July 1 as the next deadline for reaching a final deal.