Iran and world powers announce nuclear breakthrough

Iran and world powers say they have reached agreement on the "key parameters" of a potentially historic deal on Iran's nuclear programme.

The Iranian president Hassan Rouhani said the drafting of an agreement would begin immediately, after eight days of talks in the Swiss city of Lausanne that continued on Thursday past their original deadline.

Sanctions against Iran will be lifted in return for the dismantling of thousands of centrifuges, the equipment used to produce weapons-grade uranium. Iran, a signatory of the NPT which allows it a civilian nuclear programme, will retain some facilities for science and research.

The text of a binding agreement "is to finish by 30 June" Rouhani said on Twitter minutes before a joint statement between Iran and the P5+1 group of leading nations was to be made in Lausanne.

John Kerry, the US secretary of state, said that Iran would cut its enriched uranium stocks by 98 percent for 15 years. The US said that Iran's Arak plant would stop producing plutonium, which can be used in a nuclear bomb, and its Fordo facility would be converted into for civilian purposes.

Iran nuclear deal - read the key points here

Kerry said that global powers and Iran "now have parameters to resolve major issues on nuclear programme. Back to work soon on a final deal".

His comments were echoed by European powers. EU foreign policy chief Federica Mogherini hailed "good news" at the talks and said that Iran's capacity to enrich uranium would be "reduced".

The German foreign ministry said an "understanding had just been reached on key points" of an accord.

Iran's foreign minister Mohammad Javad Zarif, also said on Twitter: "Found solutions."

... now have parameters to resolve major issues on nuclear programme. Back to work soon on a final deal. US secretary of state John Kerry

The Iranian media said the deal would see Iran slash the number of its centrifuges to 6,000 from 19,000, including 1,000 at the key underground nuclear site of Fordo.

The aim before this round of talks began was to agree the main contours of a deal to be finalised by 30 June that reduces in scale Iran's nuclear programme in return for relief from painful sanctions.

The powers hope that this will make it virtually impossible for Iran to make nuclear weapons under the guise of its civilian programme and end a crisis raging for 12 years.

Global powers want Iran to scale down its nuclear programme to extend the "breakout" time needed to assemble enough nuclear material to make a bomb, which Iran has always denied seeking.

But Iranian negotiators have been under pressure from domestic hardliners not to give too much away - while also delivering on Rouhani's promise to win the lifting of sanctions.

No immediate lifting of sanctions

Global powers had refused an immediate end to all sanctions, preferring instead a phased suspension to enable them to be put back in place if Iran violates the deal.

The issue of suspending UN sanctions is particularly tricky - Iran is also subject to US and EU measures - with discord among the powers about the mechanism for a "snap-back" if needed.

The US president, Barack Obama, also needs a deal which he can sell to hostile Republicans in Congress, who remain sceptical of Iran's pledges and are threatening to push for new sanctions from April 14.

Republicans and US allies like Israel and Saudi Arabia fear that if too much of Iran's nuclear programme is left intact, it will still have the ability to obtain a nuclear bomb.

In a written statement, Israeli politicians rejected the deal, saying: "If an agreement is reached on the basis of this framework, it is an historic mistake which will make the world far more dangerous," the written comments said.