Steered by the European Union, the talks began in April and seek to bring the US back into a deal agreed in 2015. Former US president Donald Trump abandoned the accord in 2018 and began imposing tough sanctions on Iran.

Negotiations were adjourned on June 20, two days after ultraconservative Ebrahim Raisi won Iran's presidential election, and no date has been set for a resumption of dialogue.

"We are not seeking to flee the negotiation table and the... government considers a real negotiation is a negotiation that produces palpable results allowing the rights of the Iranian nation to be guaranteed," Foreign Minister Hossein Amir-Abdollahian said during an interview broadcast on Tuesday evening by state television.

The Vienna talks are "one of the questions on the foreign policy and government agenda", he said.

But "the other party knows full well that a process of two to three months is required for the new government to establish itself and to start taking decisions."

Raisi became president in early August, taking over from moderate Hassan Rouhani, the principal architect on the Iranian side of the 2015 agreement.

Raisi's government was sworn in on August 26 after receiving parliamentary approval.

The 2015 deal offered Iran an easing of Western and UN sanctions in return for tight controls on its nuclear programme, monitored by the UN.

In retaliation for Trump's withdrawal three years ago and his subsequent imposition of swingeing sanctions, Iran in effect abandoned most of its commitments under the deal.

But Trump's successor President Joe Biden wants to bring Washington back into the agreement.

The talks in Vienna involve Iran and the five other remaining parties to the deal -- Britain, China, France, Germany and Russia.

The United States also takes part in the talks but it has no direct contact with Iran.