Global powers are said to have presented Iran with a deal at nuclear talks that were described as useful. While there was no hint of an initial breakthrough, parties remained optimistic of progress in the two-day talks.
Diplomats from the so-called "P5+1" group of nations held the first formal day of talks in eight months with Iran on Tuesday.
Officials were reported to have offered Tehran limited sanctions relief, but only in exchange for a response "on the same scale" from Iran.
While there was no sign of a concrete early breakthrough in the talks, Western diplomatic sources said an offer of a limited easing of sanctions had been made. That included the resumption of metal and gold trading, as well as some international banking activity. In return, Iran would have to limit its uranium enrichment program.
"We hope very much that the Iranian side comes back showing flexibility and a willingness to negotiate," added the spokesman for EU foreign affairs chief Catherine Ashton, Michael Mann. "The ball is very much in their court."
"We had a useful meeting today, further discussions took place this evening. And we have agreed to have another meeting tomorrow," Mann said. Ashton is leading the talks.
Hours of talks
The P5+1 group formally includes permanent UN Security Council members Britain, China, France, Russia and the United States - with the "plus one" being Germany. The talks lasted several hours. Speaking from Berlin, US Secretary of State John Kerry said he hoped Iran would "make its choice to move down the path of a diplomatic solution."
Iran's enrichment of uranium to a level of 20 percent has heightened global concerns that the material could rapidly be processed for use in nuclear weapons. Iran insists its nuclear program is for peaceful purposes.
The UN Security Council has passed several resolutions demanding that Iran suspend all uranium enrichment, with a raft of US-led sanctions now in place. Israel, which is the Middle East's only nuclear power, has said Iran must be stopped before it develops military nuclear capabilities and has warned it may use military force to do so.
The P5+1 group has said it wants Iran to take the first step, such as addressing enrichment and allowing access for nuclear inspectors to facilities such as the Parchin military site (pictured above), to the south of Tehran.
The meeting follows inconclusive negotiations last year in Istanbul, Baghdad and Moscow.
rc/msh (AFP, AP, dpa, Reuters)