Iran on Tuesday laid out a hotly-awaited proposal to break the deadlock in talks with world powers over its nuclear programme, diplomats said, in a test of a thaw under new President Hassan Rouhani.
The hour-long PowerPoint presentation by Foreign Minister Mohammad Javad Zarif and his negotiators was for the first time delivered in English, officials said, underlining a new mood in the often-tense nuclear talks.
Iran's archfoe Israel has warned the world not to fall for "sweet talk" from Rouhani but Western negotiators insisted they were not naive.
No details of the proposal — entitled "Closing an Unnecessary Crisis, and Opening a New Horizon" — emerged from the closed-door talks after an initial session of two and a half hours.
On the eve of the two-day meeting, Zarif said the plan contained three steps that could settle the long-running nuclear standoff "within a year", but did not elaborate.
Zarif, travelling with his personal doctor as he battles back pain, has said he hopes the talks will sketch out a "roadmap" for higher-level negotiations.
He said the initial step could be achieved "within a month, or two, or even less".
Iran meeting with the European Union-chaired P5+1 group — the United States, Britain, France, China and Russia, plus Germany — ends a six-month hiatus over the Islamic republic's refusal to curb uranium enrichment in exchange for easing punishing international sanctions.
It also marks a revival of talks put on ice in the closing months of the presidency of conservative Mahmoud Ahmadinejad.
Rouhani, who took office in August, has promised transparency on the nuclear programme and engagement to eventually lift the trade embargo that is strangling Iran's economy by hitting oil exports and access to global banking.
EU spokesman Michael Mann underlined the "very different" atmosphere under Zarif's team.
"We have come here with a sense of cautious optimism and a great sense of determination because we believe it's really time now for tangible results," he told reporters in Geneva.
"There are signals from Tehran that they want to engage in these negotiations, that they want to be more transparent. The proof would be if they made real progress," he said.
"We are on our side ambitious to move forward quickly... The ball remains in their court," he added.
A senior US administration official said in Geneva that detail was the key and that any easing of sanctions would be "targeted, proportional to what Iran puts on the table."