Iran deal formally concluded: EU's Mogherini

European Union foreign policy chief Federica Mogherini (centre) attends a plenary session at the United Nations building in Vienna, on July 14, 2015 (AFP Photo/Joe Klamar)
European Union foreign policy chief Federica Mogherini (centre) attends a plenary session at the United Nations building in Vienna, on July 14, 2015 (AFP Photo/Joe Klamar)

Vienna (AFP) - Major world powers and Iran have formally concluded a historic deal aimed at ensuring that Iran does not obtain the nuclear bomb, the EU's foreign policy chief Federica Mogherini announced Tuesday.

"Iran Talks done. We have the agreement," she said in a tweet shortly after a final plenary session of foreign ministers from the so-called P5+1 and Iran ended in Vienna.

The announcement came on the 18th day of marathon negotiations between Iran and six world powers -- Britain, China, France, Germany, Russia and the United States.

The accord is aimed at ending a 13-year standoff over Iran's nuclear ambitions after repeated diplomatic failures and threats of military action.

The Islamic republic's archfoe Israel branded the deal a "historic mistake", but Iran and the European Union hailed it as a new chapter of hope for the world.

"I think this is a sign of hope for the entire world and we all know this is very much needed in this time," Mogherini said at the start of the plenary session, where ministers formally signed off on the accord.

Iranian Foreign Minister Mohammad Javad Zarif said the agreement, which will provide sanctions relief for Tehran's crippled economy, was a "historic moment".

"We are reaching an agreement that is not perfect for anybody but it is what we could accomplish and it is an important achievement for all of us," he said.

"We are starting a new chapter of hope."

The deal puts strict limits on Iran's nuclear activities for at least a decade and calls for stringent UN oversight, with world powers hoping that this will make any dash to make an atomic bomb virtually impossible.

In return, painful international sanctions that have slashed the oil exports of OPEC's fifth-largest producer by a quarter and choked its economy will be lifted and billions of dollars in frozen assets unblocked.