Iranian Foreign Minister Mohammad Javad Zarif on Wednesday accused Washington of being "obsessed" with sanctions as a new round of high-stakes bilateral nuclear negotiations opened in New York.
"We are committed to resolving this issue," Zarif told a US think-tank, as a State Department official confirmed to AFP that the two sides had resumed talks here late Wednesday.
But Zarif argued part of the problem blocking a deal was the US "infatuation" with sanctions.
"This deal would require the United States to lift the sanctions, and the reason Congress is objecting to this is that it wants to keep these sanctions," Zarif told the Council on Foreign Relations.
"Sanctions have become an end in themselves. Sanctions do not serve any purpose," he argued, saying during the time that the Iranian economy has been slapped with Western measures the number of the country's centrifuges has soared from 200 to 20,000.
"So sanctions have produced, just in normal calculus, 18,800 centrifuges," he said, joking it was "simple maths."
- 'Safer world' -
US Secretary of State John Kerry told lawmakers the aim was to reach a deal under which "any pathway to a bomb will be eliminated" and "we have the ability to come to you and say the world is safer, our allies in the region are safer."
"That’s the goal. We’re not there yet. I don’t know if we can get there," said Kerry, who has insisted that military action against Iran's suspect nuclear facilities has not been ruled out.
The two sides missed a July target date for a deal following an interim deal under which Iran agreed to freeze its uranium enrichment in return for access to some about $7 billion in oil revenues frozen in bank accounts around the world.
The five permanent members of the UN Security Council plus Germany -- known as the P5+1 -- are returning to the negotiating table with Iran seeking to reach a deal to scale back Tehran's nuclear activities by a new November 24 deadline.
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In return, Iran, which denies seeking nuclear weapons, wants UN and Western sanctions lifted, and is pushing for the right to enrich uranium, a process which can produce material for a bomb.
Zarif, who met Wednesday for a working lunch with European Union foreign policy chief Catherine Ashton, argued: "Iran has shown that we will live up to every agreement that we have."
A senior State Department official said the bilateral Iranian-US talks would resume again Thursday in New York before the full P5+1 plenary session on Friday.
The talks are expected to last throughout next week on the sidelines of the annual UN General Assembly, and will be joined at some point by foreign ministers.
Defending the interim deal, Kerry said Iran's program "has been halted where it was when we began and they have reduced their stockpile of 20 percent going down to zero. That’s an extraordinary thing."
US officials have stressed the November deadline will not be extended, and US lawmakers are already drawing up new legislation to impose even greater sanctions should the talks fail.
- Deep mistrust -
A new poll released Wednesday found 79 percent of over 1,000 Iranians surveyed said they would back a deal which even included Iranian assurances never to produce an atomic bomb, but a large majority admitted demands such as dismantling half of Iran's centrifuges and limiting its nuclear research would be unacceptable.
The poll also revealed deep Iranian skepticism that the West will keep promises to lift the sanctions.
Three-quarters of those surveyed said they believed the US would find some other excuse to impose sanctions, fearing the United States is out to dominate Iran or block its development.
"While the Iranian public is ready to accept taking some confidence building steps, there are obviously some clear limits," said Ebrahim Mohseni, a senior analyst at the University of Tehran.
Iranian President Hassan Rouhani "is likely to face a political backlash if he goes farther than the public is ready to support," he warned.