VIENNA/ISTANBUL - The United Nations' nuclear agency failed to persuade Iran on Wednesday to let it resume an investigation into suspected atomic bomb research, leaving the high-stakes diplomacy in deadlock.
With Iran focused on a presidential election next month, expectations had been low for the meeting between Iran and the International Atomic Energy Agency (IAEA) which has been trying for more than a year to reopen an inquiry into "possible military dimensions" of Tehran's nuclear work.
"We had intensive discussions today but did not finalize the structured approach document that has been under negotiation for a year and a half now," IAEA Deputy Director General Herman Nackaerts said after the eight-hour meeting, referring to a long-sought framework deal for the investigation.
"Our commitment to continue dialogue is unwavering. However, we must recognize that our best efforts have not been successful so far. So we will continue to try and complete this process." No date was set for future talks.
Iran's envoy, Ali Asghar Soltanieh, said both sides had put forward proposals during "intensive technical discussions" and the aim was to bridge the differences in future talks. Iran denies it has any aims to develop nuclear weapons.
The United States, which accuses Tehran of using stalling tactics at the IAEA talks and parallel negotiations with world powers, said it expected the nuclear agency to eventually urge the UN Security Council, which has imposed several sanctions resolutions on Iran, to take more action.
"At some point, the director general of the IAEA will have to return to the Security Council and say: 'I can go no further. There has been no response. You have to take further action,'" Under Secretary of State Wendy Sherman told lawmakers in Washington. That could happen in June or in September, she said.
Ashton, Jalili meet in Istanbul over Iran nukes
Later, the European Union's foreign policy chief met Iran's nuclear negotiator for dinner in Istanbul to discuss the other line of talks which are a bid to resolve a row that could ignite war in the Middle East.
The meeting between Catherine Ashton, who represents six world powers in the talks, and Saeed Jalili, who is running for president in Iran, follows a failed round of diplomacy in April.
Ashton said she hoped Jalili would respond to a "good, comprehensive, fair and balanced" proposal that the powers had already made to Iran.
"This is not a negotiating meeting, but it is an opportunity to take time to consider further the good proposals we have put forward," she said in a statement.
The two sets of talks represent distinct diplomatic tracks but are linked because both center on suspicions that Iran may be seeking the capability to assemble nuclear bombs behind the facade of a declared civilian atomic energy program.
Any movement in the decade-old standoff will now probably have to wait until after Iranians vote on June 14 for a successor to President Mahmoud Ahmadinejad.
The gap between Tehran and the powers - the United States, Russia, France, Germany, China and Britain - is wide: they want Iran to suspend its most sensitive nuclear activity. Iran wants them to recognize its "right" to refine uranium - which can have both civilian and military purposes - and to end sanctions.
Israel and the United States have threatened possible military action if diplomacy and increasingly tough trade and energy sanctions fail to make Iran curb its nuclear program.
In the latest US step to try to choke off funding for that program, the US Treasury blacklisted an exchange house and a trading company based in the United Arab Emirates on Wednesday, saying they had dealt with Iranian banks that Washington has declared off limits.
Tehran says its nuclear activity has only peaceful purposes and that it is Israel that threatens peace and stability.