Israel was surprised with the diplomatic course being taken by the US during nuclear negotiations in Geneva, including minor sanction relief, officials told Israel Radio on Saturday.
During a meeting between Prime Minister Binyamin Netanyahu and US Secretary of State John Kerry ahead of Friday's Geneva talks, the US reportedly told Israel that they would be offering minor sanctions relief to Iran.
The US also said the proposed sanction relief would not be significant.
Kerry met with Iranian Foreign Minister Mohammad Javad Zarif and EU foreign affairs chief Catherine Ashton in Geneva Friday in attempts to close "the important gaps" that remain between the sides before a deal can be signed. The meetings were set to resume on Saturday morning.
Kerry and Netanyahu met before the US secretary of state flew to Geneva to take part in negotiations on a deal in the works that would have the international community relieve sanctions on Iran in exchange for Tehran freezing its nuclear activities for six months. Kerry was reportedly expected to warn the premier of a prospective offer.
Netanyahu harshly criticized the prospective deal after the meeting with Kerry.
According to Netanyahu, Iran was getting everything it wanted at this stage, and not giving anything in return, and this at a time when Iran is under intense pressure.
According to Israel Radio, the Israeli officials said the discussion between Kerry and Netanyahu on Friday was "very difficult".
Later on Friday, US President Barack Obama called Netanyahu and updated him on the nuclear negotiations, and underscored his strong commitment to preventing Iran from obtaining a nuclear weapon.
Although the specifics of the deal under discussion are not known The Guardian reported that the "first-step agreement" is understood to include four key points:
*Iran would stop weapons-grade 20 percent uranium enrichment and turn its existing stockpile into oxide, a harmless material.
* Iran would be allowed to continue 3.5% enrichment needed for power stations, but limit the number of centrifuges being used. The deal would, however, not include any demand to remove or disable any other centrifuges.
* While still being allowed to work on its plutonium reactor at Arak, Iran would agree not to activate it for the durations of the six months. The plutonium reactor could provide for another route to nuclear weapon capability.
* Iran would not use its IR-2 centrifuges that are more advanced and capable of enriching uranium three-to-five times faster than the older model.
In exchange for these steps, the US would agree to ease some "reversible" economic sanctions, the Guardian reported, possibly by releasing some Iranian funds frozen in overseas accounts. In addition, the US could possibly relax restrictions on Iran's petrochemical, motor and precious metals industries.
The meeting, between Zarif, Kerry and Ashton lasted roughly five hours and ended late on Friday night without a deal.
An EU spokesman said after the talks that they were "good," and Kerry told journalists when he arrived back at his hotel: "We're working hard."
"It was productive but still we have lots of work to do," Iranian Deputy Foreign Minister Abbas Araqchi told reporters after the meeting.
A senior US State Department official said late on Friday that "Over the course of the evening, we continued to make progress as we worked to narrow the gaps."
"There is more work to do," the official said about efforts to reach a negotiated deal over Iran's nuclear ambitions. "The meetings will resume tomorrow (Saturday) morning."
Russian Foreign Minister Sergei Lavrov and the Chinese Foreign Minister Wang Yi were expected to join the nuclear talks in Geneva on Saturday, in further signs of headway towards an interim deal between Tehran and world powers. Michael Wilner and Herb Keinon contributed to this report.