EU foreign policy chief Catherine Ashton and Iranian Foreign Minister Javad Zarif came to Geneva Monday to relaunch negotiations over curbing Iran's nuclear programme, amid Iranian statements that jarred with recent conciliatory gestures, dpa reported.
The leaders were scheduled to ease into negotiations over dinner, diplomats said.
Formal talks were to start Tuesday morning between Zarif and Ashton, who came to the Swiss city heading a group of top diplomats from the five permanent UN Security Council member countries and Germany - the so-called P5+1.
Zarif spoke dismissively of this setup and said future talks should be led by foreign ministers from this group - China, Britain, France, Russia, the United States and Germany.
"I do not want to judge, but this constellation just did not achieve anything over the past six years," he was quoted as saying by the Iranian news agency Isna.
Both sides arrived in Geneva to discuss concrete steps that would remove suspicions that Iran's nuclear programme could be used to make nuclear weapons.
Despite recent conciliatory statements by Iran's new president Hassan Rowhani, Iran is not ready to meet the demand of the P5+1 and place parts of its enriched uranium under foreign control as a confidence-building step, Tehran's Deputy Foreign Minister Abbas Araqchi said Sunday.
The group of six are concerned that Iran could use its stock of enriched uranium in nuclear weapons, while Tehran's leaders stress that they need this material only to fuel nuclear reactors.
The talks were the first since Rowhani succeeded Mahmoud Ahmadinejad, who took a more hard-line stance on several foreign policy issues.
Israel's Prime Minister Benjamin Netanyahu warned Monday that Rowhani had just changed tactics, and that Iran was still seeking nuclear weapons.
He said pressure on Iran should not be eased. "It would be a historical mistake to give in now," he said in Jerusalem.
Israel sees Iran's nuclear programme as an existential threat and the government has not ruled out military strikes to stop the Islamic republic from getting a nuclear arsenal.
In the last round of talks in Almaty, in April, the P5+1 proposed an easing of sanctions if Iran places limits on its uranium enrichment programme, while Iran insisted that sanctions should be lifted first.