Iran has stopped expanding key nuclear sites, an International Atomic Energy Agency (IAEA) report has found. Meanwhile US President Barack Obama has urged Congress to back diplomatic efforts to end the nuclear standoff.
Iran ceased to expand its uranium enrichment capacity over the last three months, the Vienna-based agency said in a report released on Thursday.
"There is absolutely no technical reason to it. It clearly is a choice," a senior diplomat familiar with the report said, speaking on condition of anonymity.
According to the IAEA report, Iran has installed only four new first-generation IR-1 centrifuges - machines used to refine uranium - at its Natanz plant, since President Hassan Rouhani took office three months ago. That compares to 1,861 machines put in place in the three-month previous period. No new centrifuges were put into operation at the Fordo facility.
Inspectors also found that no further "major components" had been installed at a reactor being built at the Arak construction site. The UN Security Council has demanded that construction work at Arak be halted over fears the reactor is able to produce plutonium as a by-product, which could be used to produce plutonium bombs.
However the agency noted that Iran has continued to produce enriched uranium in defiance of resolutions of the UN Security Council.
Since taking office in August, Rouhani has indicated a willingness to settle the decades-long nuclear standoff with the west in a bid to ease tough international sanctions.
The report comes as Iran prepares to resume unprecedented high-level nuclear talks with the five permanent members of the UN Security Council plus Germany, known as the P5+1, in Geneva next week. The last round of talks failed to yield a result, after Iran rejected a proposal presented by the US, Britain, France, China, Russia and Germany.
The west is seeking to reach an interim deal to halt parts of Tehran's nuclear program, which it fears could be used to develop atomic weapons, in exchange for the suspension of some sanctions. Tehran has long-maintained its nuclear program is for peaceful purposes only.
Obama defends diplomacy
Fears over Iran's nuclear program have prompted many in the United States, Saudi Arabia and Israel to voice concern over the ongoing negotiations. Israel in particular has expressed opposition to any deal that does not demand Iran dismantle its entire enrichment program.
Israeli Prime Minister Benjamin Netanyahu, who has refused to rule out a military strike on Iran, said he was "unimpressed" by the report.
"Iran does not need to expand its program because it already possesses the necessary infrastructure for building a nuclear weapon," Netanyahu said.
Meanwhile US President Barack Obama was again pushed to call for more time to pursue a diplomatic deal, as lawmakers debate legislation to ramp up sanctions.
"If we're serious about pursuing diplomacy, then there's no need for us to add new sanctions on top of the sanctions that are already very effective, and that brought them [the Iranians] to the table in the first place," Obama told a White House news conference.
"Now, if it turns out they can't deliver, they can't come to the table in a serious way and get this issue resolved, the sanctions can be ramped back up ... and we've got that option," he said.
While stressing that the military option was also still on the table, he warned against the "unintended consequences" of war.
"No matter how good our military is, military options are always messy, are always difficult, always have unintended consequences, and in this situation are never complete in terms of making us certain that they don't then go out and pursue even more vigorously nuclear weapons in the future," he said.
Obama's comments come a day after US Secretary of State John Kerry warned senators that implementing new sanctions could derail the delicate negotiations.
ccp/ch (AFP, AP, Reuters, dpa)