An Iraqi policeman checks a vehicle in central Baghdad, where security… (Mohammed Jalil / European…)
BAGHDAD — Hopes for quick progress on Iran's disputed nuclear program faded rapidly Wednesday, as diplomats from six world powers and Iran collided bitterly in daylong talks intended to resolve their long-standing differences over an effort many nations fear is aimed at building a nuclear bomb.
In their second high-level meeting in as many months, representatives of the two sides offered packages of proposals designed to open a path to what is expected to be a long and difficult negotiation. But the yawning gap between the two sides quickly became apparent.
The world powers pushed Iran to give up key pieces of its nuclear program, and the Iranians complained that the six nations were not offering them a "balanced" proposal.
After discussions that lasted from 1 p.m. to midnight at a government guesthouse in Baghdad's international zone, a senior Obama administration official acknowledged to reporters that "this has been a difficult day."
Though the two sides agreed to reconvene Thursday, the clash illustrated how far the parties have to go to reach even the interim "confidence building" agreement that some U.S. officials had hinted might soon be within reach.
U.S. officials insisted that the difficult exchanges weren't surprising and might even be a sign that the sides are finally willing to engage candidly over their differences.
But if the talks collapse, as they did in January 2011, the consequences could be dire. Israel and the United States have both said they might turn to military action to halt Iran's nuclear program if diplomacy does not provide assurances that Tehran is not trying to build a bomb.
U.S. officials demanded in their proposal that Iran halt production of uranium enriched to 20% purity, a material that can be relatively easily converted for use in a nuclear bomb. They asked that Iran surrender its stockpile of such uranium and dismantle an underground site near Qom where 20% enrichment is occurring.
The world powers — the United States, Britain, France, Germany, Russia and China — offered to refrain from imposing further United Nations sanctions on Iran, but did not offer to suspend the tough U.S. and European sanctions on Iran's central bank and oil industry that have sent the Iranian economy into a tailspin in the last six months.
Officials have said they could take such steps only after Iran made irreversible moves to curb its nuclear program and came into compliance with U.N. Security Council resolutions.
Iran responded with its own package of five proposals, some dealing with the nuclear program and others with nonnuclear issues. But Iranian officials immediately began claiming the six-nation proposal was not "balanced," the official Islamic Republic News Agency reported.
In recent months, Iranian officials have repeatedly pressed for the world powers to provide relief on the sanctions and have declared that enrichment is their right under the Nuclear Nonproliferation Treaty, to which Iran is a signatory.
The senior administration official, who declined to be identified because of the sensitivity of the subject, said the conflicts were not just about the sanctions, but also about the demands regarding 20% enrichment and other issues.
"I would have expected nothing but for them to say that this was 'unbalanced,' " the official said. "This is a negotiation in which we both want to get the most and give the least."
But the official added that the harsh words were a sign that, unlike in the past when the two sides have often avoided direct discussion, "you're getting down to the issues that matter.… I take that as a good sign, not a bad one."
Both sides still have powerful reasons to want to keep the negotiations on track. The sanctions are battering Iran's economy, and the Obama administration knows that a failure of the talks could invite an Israeli attack on Iran that could set off a regional war, drive up oil prices and imperil the global economic recovery and President Obama's reelection bid.
U.S. officials and other Western diplomats predicted after the meeting that the sides would schedule more meetings. But the clash highlighted how many pitfalls may lie ahead as the world powers try to deal quickly with the problem.
Iranian and U.S. officials did not have a bilateral meeting during the session, though others did. The senior administration official said such a meeting would have been unlikely, given the two nations' bitter history. Still, such a session would have been an encouraging sign that Tehran wanted to work out its points of tension with Washington.
Ray Takeyh, a former administration advisor on Iran, said the Iranians probably have now gotten the signal that they will have to make sacrifices to settle an issue that has upset numerous nations.
"The Iranians are hoping to do a little and get a lot back," he said in an email. "It was useful for [the world powers] to disabuse them of that illusion."
He predicted that the talks will continue.
"Both sides have laid out their opening positions and much haggling will continue to take place, I suppose," he said.