Iran's foreign minister, Mohammad Javad Zarif, has said that a deal to end a nuclear standoff with the international community could be reached at talks in Swiss city of Geneva later this 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," Zarif told France 24 television ahead of talks in Paris with his French counterpart Laurent Fabius.
His comments come two days after Iran's Supreme Leader Ayatollah Ali Khamenei voiced his support for Iran's nuclear talks, but reserved an amount of pessimism about their results.
"No one should see our negotiating team as compromisers," Khamenei, Iran's top decision-maker, was quoted as saying on his official website on Sunday.
"I am not optimistic about the negotiations but, with the grace of God, we will not suffer losses either."
The new round of talks between Iran and representatives of world powers is scheduled in Geneva for November 7 and 8. They are the second round of talks since moderate President Hassan Rouhani took office in August.
It comes less than a month after the last round of talks ended on an upbeat note, with Tehran laying out a road map to end the showdown over its nuclear ambitions.
Michael Mann, the spokesman for the European Union foreign policy chief Catherine Ashton, who lead the negotiations in October on behalf of world powers, said the Iranian presentation had been "very useful".
IAEA chief to visit Iran
The talks are aimed at curbing Iran's sensitive nuclear work in exchange for a relief from international sanctions strangling Iran's economy.
The West suspects the nuclear programme is masking a military drive despite repeated Iranian denials.
Ahead of the talks, Israel opposed the diplomatic path, saying Tehran was trying to buy time and trick the world into dropping tough sanctions without making any significant concessions.
"Iran is willing to give a little and get a lot, if not everything," Netanyahu said. "It would be a historic mistake to lift the pressure now, just before the sanctions reach their goal," said Benjamin Netanyahu, the Israeli prime minister.
Earlier in the day, Iran's nuclear chief Ali Akbar Salehi said that Yukiya Amano, UN nuclear watchdog chief, was expected in Tehran on Monday.
Salehi hopes "to reach an agreement with the director of the International Atomic Energy Agency and issue a joint statement", the website of state broadcaster IRIB quoted him as saying.
The International Atomic Energy Agency and Iran have held a series of meetings since early 2012 over a stalled IAEA investigation into suspected nuclear bomb research by Iran.
Salehi said he had invited Amano to visit on that day and that Amano, IAEA director-general, had expressed his "inclination" to do so, state television said.
It would be Amano's first visit to Tehran since May last year.