Iran and six world powers began a "critical" week of nuclear negotiations in Vienna still far apart despite daily contacts over the past month, a senior administration official said Monday.
With a negotiating deadline of July 20 now nearly a month away, the group held a round of nation-to-nation meetings with the Iranians last week, including an unusual session between high-level U.S. and Iranian officials.
Though the two sides have some better ideas about how they could theoretically bridge the gaps, there remain "significant differences" between them, the official told reporters in a briefing.
The official, who declined to be identified under administration ground rules, was unable to say that the two days of U.S.-Iranian meeting had yielded progress. That meeting included two senior U.S. officials, Deputy Secretary of State William Burns and White House foreign policy aide Jacob Sullivan.
Iran and the six powers — the United States, Germany, Britain, France, Russia and China — have been seeking a deal that would ease economic sanctions on Iran in exchange for curbs aimed at ensuring that Tehran doesn't develop nuclear weapons capability.
The comments reinforced the impression that the two sides have been at an impasse since their meeting in May, each waiting for the other to make major concessions.
Under an interim deal reached in November, the two sides are entitled to extend their talks for an additional six months. Yet unless negotiators can show they have made progress, a wary Congress and hardliners in Iran may resist the request for more time.
"There are still significant gaps," the official said. "We don't have illusions about how difficult it will be to close those gaps."
"This week is a critical one for the comprehensive negotiations," the official said.
Although negotiators for several countries have said more time may be needed, this official said the group is not currently talking about seeking an extension. They believe a quick completion of the talks would be preferable and are pushing toward it, the official said.
The official acknowledged that any additional negotiating time would have to be agreed upon by the two sides. That could be tricky, analysts say.
The United States and Iran, the key players in the group, each badly want a deal. But if they were to come home with terms that were perceived as too lenient, they would come under fire from skeptical opponents of a deal.