Delegates from Iran, the European Union, the US, Russia, Britain, France and Germany met at a conference center in Geneva, with EU foreign policy chief Catherine Ashton greeting Saeed Jalili, Iran's chief negotiator, in the foyer.

"About 75 percent" of the three-hour morning session was devoted to nuclear issues, said an official close to the talks. That was significant, because Iran had come to the table insisting that the negotiations address Iran's nuclear program only peripherally — if at all.

Specific sensitive points included a renewed call by the world powers for an end to Tehran's program of uranium enrichment — an activity that Iran says is not up for negotiations, said the official, who asked for anonymity in exchange for discussing the confidential negotiations.

Tehran says it does not want atomic arms, but as it builds up its capacity to make such weapons, neither Israel nor the US has ruled out military action if Tehran fails to heed UN Security Council demands to freeze key nuclear programs.

Ashton and senior officials from the six powers noted that doubts about the peaceful nature of Iran's nuclear program were among the sources of instability in the region, said the official.

Jalili's comments included other themes — including mention of last week's assassination of an Iranian nuclear scientist and the wounding of an associate, the official said.

Nations have a right to enrich uranium domestically and Iran insists it is doing so only to make fuel for an envisaged network of reactors and not to make fissile warhead material. But international concerns are strong because Tehran developed its enrichment program clandestinely and because it refuses to cooperate with an IAEA probe following up on suspicions that it experimented with components of a nuclear weapons program — something Iran denies.

Officials described the initial meeting as encouraging as the two sides broke for lunch of duck with olives, char fillet with sage, rice pilaf and desert. Jalili planned to come back to the other participants with a response to their presentations, one official said.

Two days of talks have been scheduled. The world powers hope to get Iran to negotiate on its enrichment program — a request it has firmly rejected in the past, the official said, adding that the powers would then meet with Iran again next year in Turkey, an Iranian ally and Tehran's choice of venue.

Blurb :

Senior officials from the six powers noted that doubts about the peaceful nature of Iran's nuclear program were among the sources of instability in the region.