U.S. and Iranian envoys Saturday had their highest-level diplomatic contact in 29 years, but the seven-nation gathering in Geneva on Tehran's nuclear program was quickly brought to a halt by Iran's refusal to say whether it would suspend uranium enrichment.
U.S. Undersecretary of State William J. Burns joined European Union foreign policy chief Javier Solana and other diplomats in an attempt to coax Tehran, represented by Saeed Jalili, to agree to a deal aimed at negotiating an end to Iran's nuclear program.
Instead, the diplomats were left wondering whether the Islamic Republic intended to join negotiations or whether it was simply playing for time as the Bush administration winds to an end.
Solana, clearly frustrated, said at a news conference in Geneva: "We have not got a clear answer. . . . We didn't get an answer 'yes' or 'no.' "
As a result, Tehran was given another deadline of two weeks from now to provide a final answer to the group, which comprises the United States, Russia, China, Britain, France and Germany.
A senior U.S. official in Washington said the United States would press to levy additional economic and political sanctions on Tehran if it continued to delay.
"We'll have to see," said the official, who declined to be identified because of the sensitivity of the matter. "If that is the case, more things will be added to the disincentive side of the ledger in short order."
State Department spokesman Sean McCormack, also in Washington, gave a warning to Iran: "We hope the Iranian people understand that their leaders need to make a choice between cooperation, which would bring benefits to all, and confrontation, which can only lead to further isolation."
The inconclusive meeting was a setback for the Bush administration, which set aside its long-declared policy of avoiding contact with Iran until it agreed to suspend uranium enrichment. U.S. officials allege that Tehran seeks a nuclear bomb and fear that the enrichment effort will eventually give it the know-how to build one. The Iranians contend that the enrichment is for peaceful purposes.
The meeting was the most important diplomatic encounter since the 1979 Islamic Revolution between the United States and Iran, which President Bush six years ago labeled a member of an "axis of evil."
U.S. and Iranian officials have met in recent years to discuss Iraq's security, and senior diplomats have exchanged greetings from time to time in various regional meetings. But U.S. officials have maintained that isolating Iran, led by hard-line President Mahmoud Ahmadinejad, was an important point of leverage that they would be unwise to give up.
Even before the meeting, Iran's ambassador to Switzerland, Keyvan Imani, said Tehran remained opposed to suspension of enrichment, which it says is allowed it as a signatory of the Nuclear Nonproliferation Treaty.
"It is not in Iran's agenda to discuss this issue," Imani told reporters.
Jalili, Iran's nuclear negotiator, offered a more upbeat account of the meeting, saying afterward that the talks were "constructive and progressing," and that "on the manner of continuing the negotiations, we have understood better our mutual positions."
At the meeting, Burns delivered a "clear, simple message" that the United States supports the package of economic and political incentives offered by the group, backs united efforts by the six powers, and insists that Tehran suspend enrichment, McCormack said in a statement. He said that Burns held no other meeting with any Iranian officials.
The six powers have proposed an opening stage of negotiations, called "freeze for freeze," in which they would agree to not impose any further sanctions on Tehran for a six-week period if the Iranians agreed not to add to their nuclear program. During this period, the two sides would work out a framework for substantive negotiations, which would only begin once Iran suspended its uranium enrichment efforts.
Ray Takeyh, an Iran specialist at the Council on Foreign Relations, said the Iranians may feel they have a strong incentive to continue delaying on a deal because they may now think they are seeing a pattern of U.S. concessions.
From the Iranian viewpoint, Takeyh said, the American "red lines" -- nonnegotiable demands -- might appear to be disappearing so quickly they are no longer red. "They're purple, they're mauve, they're anything but red," he said.
Yet he said the Iranians may eventually agree to a "freeze for freeze" deal -- because they may believe that Bush is so weak that they could win more favorable terms from him than from his successor.
Although Europeans and Americans have described the package of potential economic and political incentives as generous, some analysts say it lacks a key element that has left Iran balking: a promise that the U.S. would renounce any plans to attempt to topple Iran's government.
"The main, main issue for Tehran is the security guarantee, and that is lacking," said Saeed Leylaz, an Iranian political analyst. "Iranian and American problems are security problems, not diplomatic ones."
The senior U.S. official emphasized that by sending Burns, Washington had hoped to accomplish several goals, including provoking a new debate among Iranians about the advantages of accepting the package of incentives, and increasing the unity of the six other nations.
Iran faces numerous economic problems that may make it seek to improve its international standing.
Tehran says it needs nuclear power for its growing population's electricity needs. Chronic summer power outages caused in part by international firms' fears of doing business with Iran have hurt Iranian commerce.
Richter reported from Washington and Daragahi from Tehran. Special correspondent Ramin Rostaghim in Tehran contributed to this report.