Iran and six world powers, including the United States, exchanged proposals at talks in Kazakhstan today aimed at breaking a decade-old stalemate over Tehran's nuclear ambitions.
The US, Russia, China, Britain, France and Germany, the so-called P5+1, reportedly offered Iran modest sanctions relief if it curbs the most sensitive aspects of its uranium enrichment activities.
"We have come here with a revised offer and we have come to engage with Iran in a meaningful way," the European Union's foreign policy chief, Catherine Ashton, who negotiates with Iran on behalf of the world powers, said in a statement.
Iranian officials said they had several counterproposals ready for the talks, the first high-level meeting between the two sides in eight months.
"Which versions we present depends on what the 5+1 put forward," a member of the Iranian delegation told reporters. "Our offer will be of the same weight as their offer."
Iran insists its nuclear programme is solely for civilian purposes, and demands "reciprocity" where concessions by one side are matched simultaneously by ones of equal value by the other.
Western officials cautioned against expecting any breakthrough at the negotiations in Almaty, the former Kazakh capital, which were due to end later today. Hopes are centred on holding further talks soon on practical steps to ease tensions.
The P5+1 are understood to be offering Iran permission to resume its gold and precious metals trade as well as some international banking activity which are currently under sanctions.
Iran is seeking a far more significant easing of oil and financial sanctions that are battering its economy.
Many analysts believe there can little progress in nuclear talks before a new Iranian president is inaugurated in August.
"The likelihood, given Iran's imminent preoccupation with June's presidential elections, is that Kazakhstan is a 'holding' meeting for another high-level discussion in the autumn," Scott Lucas, an Iran expert at Birmingham University in England, wrote on his EA WorldView blog.
While previous talks have ended in deadlock, they have at least made visible the contours of an eventual accord. Iran would have to limit its enrichment of uranium to 3.5 per cent, the level needed to fuel power-generating nuclear reactors.
It also would have to provide verifiable guarantees, including intrusive inspections, that no material is diverted to possible military use. In return, the six world powers gradually would have to lift sanctions. US Secretary of State John Kerry, visiting Berlin, said there is a "diplomatic path" in the nuclear crisis and expressed hope that "Iran itself will make its choice to move down the path of a diplomatic solution".