When asked Monday on the eve of the talks whether the US administration is willing to accede to Tehran's chief demand, a US negotiator said, "We are prepared to talk about what President Obama said in his address at the UN General Assembly, and that is that he respects the rights of the Iranian people to access a peaceful nuclear program."

The senior US official said on condition of anonymity, "What that is a matter of discussion."

"We hope we can begin translating the positive tone in New York to more specific actions," said the senior US official.

Obama left the US position on the issue vague, repeatedly saying in recent weeks, including during his United Nations General Assembly speech, that Iran has the right to "access" peaceful nuclear energy.

US officials, Western allies and Iranian officials arrived in Geneva Monday voicing cautious optimism about the first round of talks overseen by Iranian President Hasan Rouhani's government.

The talks, the latest since negotiations in April, include the five permanent members of the United Nations Security Council, plus Germany, a diplomatic bloc known as the P5+1.

The US administration’s stance, which President Barack Obama has hinted at broadly in recent weeks, comes as international negotiations aimed at curbing Iran's nuclear work resume Tuesday in Geneva.

Iran's new government says it wants to continue enriching uranium for civilian uses and over the weekend declared it wouldn't ship nuclear materials out of the country.

But key US allies in the region, particularly Israel and Saudi Arabia, insist that Tehran should be denied any facilities to enrich uranium because of the potential for military uses, according to US and Arab officials.

Members of Congress also are pressuring the White House to seek a complete dismantling of Iran's centrifuge machines. A group of 10 Republican and Democratic lawmakers wrote President Obama on Friday to urge an increase in sanctions on Iran until it agrees to a complete enrichment freeze.

NTJ/BA