Announcing the failure of two days of negotiations, EU foreign policy chief Catherine Ashton said no new date for another meeting had been set. She blamed what the six consider unrealistic demands by Iran - an end to U.N. sanctions and agreement that Iran could continue to enrich - for the disappointing results.
Proposals by the six for improved U.N. monitoring of Iran's nuclear activities were rejected by Tehran, as were attempts to kickstart dialogue through reviving a subset of international talks focusing on Iran shipping out a limited amount of its enriched uranium in exchange for fuel for its research reactor, Ashton said.
"We had hoped to have a detailed and constructive discussion of those ideas," she said. "But it became clear that the Iranian side was not ready for this unless we agree to preconditions related to enrichment and sanctions.
"Both these preconditions are not the way to proceed," she told reporters.
While no new talks were planned, Ashton said "our proposals remain on the table.
"Our door remains open. Our telephone lines remain open.
"The process can go forward if Iran chooses to respond positively," she said. "We will now wait to see whether they do."
Tehran denies that it wants nuclear arms, insisting it wants only to make peaceful nuclear energy for its rising population. But concerns have grown - because its uranium enrichment program could also make fissile warhead material, because of its nuclear secrecy and also because the Islamic Republic refuses to cooperate with U.N. attempts to investigate suspicions that it ran experiments related to making nuclear weapons.
While the six went into the first day of talks Friday formally focused at freezing Iran's uranium enrichment program, Tehran has repeatedly said this activity is not up for discussion. Instead, Iranian officials came to the table with an agenda that covered just about everything except its nuclear program: global disarmament, Israel's suspected nuclear arsenal, and Tehran's concerns about U.S. military bases in Iraq and elsewhere.
As talks resumed Saturday, Iranian delegate Abolfazl Zohrevand said the atmosphere was "positive."
"Both sides showed the willingness that a solution can be achieved to reach active cooperation on various issues," he told AP Television News.
But diplomats from two other delegations familiar with the negotiations were less bullish with one suggesting shortly before the end of the meeting that the talks were in trouble because Iran was sticking to its demands on the lifting of sanctions and acceptance of Iran's enrichment activities.