The official told reporters in Washington that it is "quite possible" that the P5+1 – including Britain, China, France, Germany, Russia and the United States – will reach a deal with Iran when talks resume in Geneva on November 20.
According a report released by the International Atomic Energy Agency on Thursday, Iran has significantly slowed work on nuclear projects that could be used to make weapons. According to the official, the slowdown was a result of a diplomatic decision by Tehran, and not of technical difficulties.
The senior official said the development is positive but added that it is difficult to assert whether it was a "sign of good faith."
Nevertheless, the world powers have asked Congress to refrain from imposing new sanctions on Iran while the negotiations are in progress, the official said. The U.S. administration believes that new sanctions would spur Iran's nuclear development.
The official stressed that the U.S. does not believe that Iran has the "right" to enrich uranium, adding that a deal with Tehran will not stipulate anything to that effect.
Should Iran and the P5+1 reach an agreement, relief from sanctions will not amount to more than $15 billion, the official said. The Islamic Republic loses $5 billion a month as result of the economic measures aimed at curbing its nuclear program.
PM presses France on Iran
Meanwhile, Prime Minister Benjamin Netanyahu pressed France not to weaken in its stance toward Iran in the upcoming talks, days before President Francois Hollande is due to visit Israel.
Iran has accused France of blocking agreement last week at talks between Tehran and six world powers in Geneva.
"We hope that France will not weaken," Netanyahu told Le Figaro daily in an interview. "We salute (Hollande's) consistent and determined position on the Iranian issue."
Netanyahu reiterated his government's opposition to Iran pursuing any research that could lead to the development of a nuclear weapon, saying it should not possess heavy water reactors or centrifuges used to enrich radioactive material. Tehran says it wants nuclear energy for electricity, not bombs.
Also on Friday, Foreign Policy magazine's The Cable blog reported that Israeli ambassador to the U.S. Ron Dermer and AIPAC, the influential pro-Israel lobby in Washington, are "storming Capitol Hill" in an attempt to "discredit" the Obama administration's efforts to reach an agreement with Tehran. The report cited multiple Congressional aides.
According to the magazine, the campaign comes alongside a visit to Washington by Economy Minister Naftali Bennett, who is also attempting to turn U.S. lawmakers against the deal.
"The campaign includes one-on-one briefings with lawmakers that provide data that strays from official U.S. assessments," the report said.
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