An outline agreement on the future shape of Iran’s nuclear programme has been reached after marathon talks with six major powers in Switzerland.
The European Union and Iran announced the deal after eight days of negotiations in Lausanne.
EU foreign policy chief Federica Mogherini said Iran’s “enrichment capacity and stockpile would be limited”.
A comprehensive nuclear accord would be drafted by 30 June, she added.
Iran denies Western claims it is trying to build a nuclear weapon. It entered negotiations in order to see sanctions lifted.
The talks between the so-called P5+1 – the US, UK, France, China and Russia plus Germany – and Iran at Lausanne’s Beau-Rivage Palace hotel were supposed to end on 31 March but overran in the search for a deal.
Speaking at a news conference alongside Iranian Foreign Minister Javad Zarif after agreement was reached, Ms Mogherini said a “decisive step” had been achieved.
“We have reached solutions on key parameters of a joint comprehensive plan of action,” she said.
As well as imposing limitations on Iran’s nuclear capabilities, a final deal would also include the “termination” of nuclear related economic and financial sanctions by the EU and US.
Negotiators would now start “drafting the text” of the plan “guided by the solutions”, Ms Mogherini added.
Earlier, in a tweet, Iranian Foreign Minister Javad Zarif said: “Found solutions, ready to start drafting immediately.”
Also on Twitter, Germany’s foreign ministry said: “Agreement for framework on final agreement reached.”
And US Secretary of State John Kerry tweeted: “Big day… Back to work soon on final deal.”
But Israeli leader Benjamin Netanyahu also took to Twitter to declare: “Any deal must significantly role back Iran’s nuclear capabilities and stop its terrorism and aggression.”