ALMATY, Kazakhstan: World powers began a new round of high-level talks with Iranian officials Tuesday, trying to find a way out of a yearslong tussle over Tehran's nuclear program and its feared ability to make atomic weapons in the future.

Few believe the latest attempt to forge a compromise will yield any major breakthroughs, but negotiators are optimistically casting it as a stepping stone toward reaching a workable solution.

Officials described the latest diplomatic discussions as a way to build confidence with Iran as the country steadfastly maintains its right to enrich uranium in the face of harsh international sanctions.

"The offer addresses the international concern on the exclusively peaceful nature of the Iranian nuclear program, but it is also responsive to Iranian ideas," said Michael Mann, spokesman for EU foreign policy chief Catherine Ashton, who is leading the negotiations. "We've put some proposals forward which will hopefully allow Iran to show some flexibility."

Mehdi Mohammadi, a member of the Iranian delegation, said Tehran was prepared to make an offer of its own to end the deadlock but will resist some of the West's core demands.

The Obama administration is pushing for diplomacy to solve the impasse but has not ruled out the possibility of military intervention in Iran to prevent it from acquiring a nuclear weapon. Israel has threatened it will use all means to stop Iran from being able to build a bomb, potentially as soon as this summer, raising the specter of a possible Mideast war.

A senior U.S. official at the talks said Monday that some sanctions relief would be part of the offer to Iran but refused to elaborate. The new relief is part of a package that the U.S. official said included "substantive changes."

The official acknowledged reports earlier this month that sanctions would be eased to allow Iran's gold trade to progress, but would neither confirm nor deny they are included in the new relief offer, and spoke only on condition of anonymity to discuss the sensitive diplomatic talks more candidly.

In a statement before the talks began Tuesday, the Interfax news agency cited Russia's envoy as saying the easing of sanctions was possible only if Iran can assure the world that its nuclear program is for exclusively peaceful purposes.

"There is no certainty that the Iranian nuclear program lacks a military dimension, although there is also no evidence that there is a military dimension," Russian Deputy Foreign Minister Sergei Ryabkov said.

China's Foreign Ministry said diplomacy offered the only route to resolve the dispute and called for all sides to show flexibility.

"We think the Iranian nuclear issue is very complicated and sensitive. All parties should have firm confidence in peacefully resolving the issue through dialogue and negotiation and take an objective and pragmatic attitude," Chinese Foreign Ministry spokeswoman Hua Chunying said at a daily briefing in Beijing.

Members of the Chinese and Iranian delegations met at a bilateral session before the main talks got under way.

Interfax cited an unidentified Iranian delegation member as saying Iran might also hold one-on-one talks with Russia, but ruled out direct negotiations with the United States in Almaty.

Officials from both sides have set low expectations for a breakthrough in Almaty - the first time the high-level negotiators have met since last June's meeting in Moscow that threatened to derail the delicate efforts.

While Mann acknowledged the Almaty talks would unlikely lead to a firm, he insisted that it remained an important stepping stone toward a definitive solution.

"We're not interested in talks just for talk's sake. We're not here to talk, we're here to make concrete progress," he said.

The first session talks are being held in private at a hotel in Almaty, Kazakhstan's largest city, and were deemed so sensitive that reporters were not allowed on the premises Tuesday save for a small handful of TV cameras and photographers allowed to watch Ashton greet Saeed Jalili, secretary of Iran's Supreme National Security Council.

The opening round Tuesday afternoon lasted 2 ½ hours.

Tehran maintains it is enriching uranium only to make reactor fuel and medical isotopes, and insists it has a right to do so under international law. It has signaled it does not intend to stop, and U.N. nuclear inspectors last week confirmed Iran has begun a major upgrade of its program at the country's main uranium enrichment site.

Over the last eight months, the international community has imposed harsh economic sanctions on Iran that U.S. officials said have, among other things, cut the nation's daily oil output by 1 million barrels and slashed its employment rate. Western powers have hoped that the Iranian public would suffer under sanctions so the government would feel a moral obligation to slow its nuclear program.

The six world powers - United States, Russia, China, Britain, France and Germany -want Iran to suspend enrichment in its underground Fordo nuclear facility, and to ship its stockpile of high-grade uranium out of the country.

Mohammadi said that the shuttering of Fordo was "out of the question."

Negotiators hope that easing some of the sanctions will make Tehran more agreeable to halting production of 20 percent enriched uranium - the highest grade of enrichment that Iran has acknowledged and one that experts say could be turned into warhead grade in a matter of months.

Mohammadi said Iran would only agree to that stipulation on the condition of UN Security Council sanctions being suspended.

But an analysis released Monday by the International Crisis Group concluded that the web of international sanctions have become so entrenched in Iran's political and economic systems that they cannot be easily lifted piece by piece. It found that Tehran's clerical regime has begun adapting its policy to the sanctions, despite their crippling effect on the Iranian public. Doing so, the analysis concluded, has divided the public's anger "between a regime viewed as incompetent and an outside world seen as uncaring."

Iran has been unimpressed with earlier offers by the powers to provide it with medical isotopes and lift sanctions on spare parts for civilian airliners, and new bargaining chips that Tehran sees as minor are likely to be snubbed as well. Iran insists, as a starting point, that world powers must recognize the republic's right to enrich uranium.