Secretary of State John Kerry will fly to Geneva on Friday to participate in the negotiations between Iran and six world powers on a deal to cap some of the country's atomic programs in exchange for limited relief from sanctions stifling Iran's economy.
Kerry's visit comes as Iran's chief nuclear negotiator signaled progress at the negotiating table, saying the six had accepted Tehran's proposals on how to proceed, even as Israeli Prime Minister Benjamin Netanyahu called the emerging agreement the "deal of the century" for Iran.
A senior state department official said Friday that Kerry has been open to the possibility of traveling to Geneva for the talks "if it would help narrow differences." The official said European Union's top diplomat, Catherine Ashton, asked Kerry to attend the latest round of discussions.
The official, who spoke to reporters on condition of anonymity, called the negotiations "a complex process" and said Kerry was "committed to doing anything he can" to help.
An EU spokesman said French Foreign Minister Laurent Fabius will join Kerry at the talks "to help narrow differences in negotiations" -- a last-minute decision that suggests a deal could be imminent, Reuters reported.
Even if an agreement is reached, it would only be the start of a long process to reduce Iran's potential nuclear threat, with no guarantee of ultimate success.
Netanyahu said Friday that he "utterly rejects" the emerging nuclear deal between western powers and Iran, calling it a "bad deal" and promised that Israel will do everything it needs to do to defend itself.
"I understand the Iranians are walking around very satisfied in Geneva as well they should because they got everything and paid nothing," Netanyahu told reporters before meeting with Kerry in Tel Aviv.
"They wanted relief of sanctions after years of grueling sanctions, they got that. They paid nothing because they are not reducing in any way their nuclear enrichment capability. So Iran got the deal of the century and the international community got a bad deal," Netanyahu said.
"This is a very bad deal and Israel utterly rejects it. Israel is not obliged by this agreement and Israel will do everything it needs to do to defend itself and defend the security of its people," he said.
Israel believes Iran is trying to develop a nuclear weapon, and says international pressure should be stepped up, not eased.
Tehran's chief nuclear negotiator, Abbas Araghchi, told Iranian state TV on Thursday that the United States, Russia, China, Britain, France and Germany "clearly said that they accept the proposed framework by Iran." He later told CNN that he thinks negotiators at the table are now "ready to start drafting" an accord that outlines specific steps to be taken.
Though Araghchi described the negotiations as "very difficult," he told Iranian state TV that he expected agreement on details by Friday, the last scheduled round of the current talks.
The upbeat comments suggested that negotiators in Geneva were moving from broad discussions over a nuclear deal to details meant to limit Tehran's ability to make atomic weapons. In return, Iran would start getting relief from sanctions that have hit its economy hard.
State Department spokeswoman Jen Psaki said Kerry is expected to meet Friday with Ashton, and Iranian Foreign Minister Mohammad Javad Zarif. Britain's Foreign Secretary
William Hague and German Foreign Minister Guido Westerwelle were also expected to join Kerry on Friday, Reuters reported.
The talks are primarily focused on the size and output of Iran's enrichment program, which can create both reactor fuel and weapons-grade material suitable for a nuclear bomb. Iran insists it is pursuing only nuclear energy, medical treatments and research, but the United States and its allies fear that Iran could turn this material into the fissile core of nuclear warheads.
President Obama, in an interview with NBC on Thursday, described any sanctions relief as "modest" but said core sanctions against Iran would remain in place.
"Our job is not to trust the Iranians," Obama said. "Our job is to put in place mechanisms where we can verify what they're doing and not doing when it comes to their nuclear program."
International negotiators representing the six powers declined to comment on Araghchi's statement. Bur White House spokesman Jay Carney elaborated on what the U.S. calls a "first step" of a strategy meant to ultimately contain Iran's ability to use its nuclear program to make weapons.
An initial agreement would "address Iran's most advanced nuclear activities; increase transparency so Iran will not be able to use the cover of talks to advance its program; and create time and space as we negotiate a comprehensive agreement," Carney told reporters in Washington.
The six would consider "limited, targeted and reversible relief that does not affect our core sanctions," he said, alluding to penalties crippling Tehran's oil exports. If Iran reneges, said Carney, "the temporary, modest relief would be terminated, and we would be in a position to ratchet up the pressure even further by adding new sanctions."
He described any temporary, initial relief of sanctions as likely "more financial rather than technical." Diplomats have previously said initial sanction rollbacks could free Iranian funds in overseas accounts and allow trade in gold and petrochemicals.
The last round of talks three weeks ago reached agreement on a framework of possible discussion points, and the two sides kicked off Thursday's round focused on getting to that first step.
Thursday's meeting ended about an hour after it began, followed by bilateral meetings, including one between the U.S and Iranian delegations. EU spokesman Michael Mann said the talks were "making progress."
Before the morning round, Zarif, the Iranian foreign minister, met with the EU's Ashton, who is convening the meeting. Asked afterward about the chances of agreement on initial steps this week, Zarif told reporters: "If everyone tries their best, we may have one."
After nearly a decade of deadlock, Iran seems more amenable to making concessions to the six countries. Iran's new president, Hassan Rouhani, has indicated he could cut back on the nuclear program in exchange for an easing of sanctions.
Despite the seemingly calmer political backdrop, issues remain.
Iranian hardliners want a meaningful — and quick — reduction of the sanctions in exchange for any concessions, while some U.S. lawmakers want significant rollbacks in Iran's nuclear activities in exchange for any loosening of actions.
The Associated Press contributed to this report.