Iran said Tuesday a deal was possible on its disputed nuclear programme at talks due to resume Thursday with world powers, as it announced the UN atomic watchdog chief would visit next week.

"I believe it is even possible to reach that agreement this week but I can only talk for our side, I cannot talk for the other side," Foreign Minister Mohammad Javad Zarif told France 24 television.

"We need to enter these discussions with an open eye but in good faith. We are prepared to reach an agreement," he added.

The so-called P5+1 group of major powers will meet Iran's nuclear team in Geneva on Thursday and Friday for the latest round of negotiations revived after the election of Iranian President Hassan Rouhani, a reputed moderate.

Both sides hope to build on a meeting last month hailed as "substantive" by all sides, at which Iran's delegation outlined a new proposal and met bilaterally with the US for the first time since 2009.

The United States is part of the P5+1, which includes Britain, China, France, Russia and Germany.

According to Iranian officials, the proposal -- whose details have been kept under wraps -- envisages a first and a last step which Tehran hopes can be implemented within three months and a year respectively.

Iran's lead negotiator in Geneva, Deputy Foreign Minister Abbas Araqchi, said Monday a "negotiation framework" had been agreed.

"Our expectation now is to begin discussions on content and then move towards an agreement on content," Araqchi told the ISNA news agency.

Ahead of the meeting, French Foreign Minister Laurent Fabius told his Iranian counterpart that the negotiations could not go on forever.

"It is necessary for Iran to respond in a concrete and verifiable manner to the concerns of the international community and ... the time for negotiations is not unlimited," Fabius told Zarif during a meeting in Paris, a statement from his spokesman said.

Iran is also hoping to push forward talks with the International Atomic Energy Agency.

On Tuesday, Iranian nuclear chief Ali Akbar Salehi said IAEA head Yukiya Amano would visit Tehran.

Salehi said that he had "invited Amano to visit Tehran on November 11 and he expressed his willingness to come", adding that he hoped "to reach an agreement with (Amano) and issue a joint statement".

Ten rounds of talks with the IAEA since November 2011 have made little headway on the decade-long stand-off over the nuclear programme, but Rouhani's election has sparked optimism.

However, while the atmosphere has also been positive at the P5+1 talks, conducted in English for the first time, key differences remain as Iran seeks relief from crippling international sanctions.

A senior Western diplomat speaking on condition of anonymity said after the last round of talks in Geneva that an immediate solution was not in sight.

"The differences remain very large in terms of what the steps should include," the source said.

Iran hopes to lift sanctions, while Western powers and Israel seek to curb its uranium enrichment, which they say is aimed at developing a nuclear weapon, an allegation Tehran denies.

In an interview with Israel's Channel 10 News this weekend, lead US negotiator Wendy Sherman defined "progress" as stopping the nuclear programme from advancing while negotiators reach a comprehensive agreement.

She said Washington was prepared to offer "very limited, temporary, reversible sanctions relief" while maintaining the "fundamental architecture of the oil and banking sanctions -- which we will need for a comprehensive agreement, not for a first step".

Khamenei says negotiators not 'compromisers'

Ali Vaez, senior Iran analyst at the International Crisis Group, cautioned that negotiators still have a long way to go, pointing out that each side will have to hold its hardliners in check.

"Although the P5+1 has -- for the first time -- agreed to define the broad contours of an end-game, spelling it out will be groundbreaking and will require more discussion with Iran and within the P5+1," he told AFP.

This week's meeting will be the second such gathering since Rouhani took office in August pledging to resolve the nuclear dispute and lift the sanctions through constructive engagement.

However the conduct of his nuclear team, overseen by Zarif, has come under fire from hardliners wary of compromise on what Iran sees as its right to nuclear enrichment.

Supreme leader Ayatollah Ali Khamenei, who has the final word on all major policy issues, threw his weight behind the nuclear team on Sunday.

"No one should see our negotiating team as compromisers," he said, adding that they needed national support in their "difficult mission".

But Khamenei also said he did not "think the negotiations will produce the results expected by Iran", adding that he is "not optimistic".