President Mahmoud Ahmadinejad, in his first comment on last week's talks in Geneva between Iran and six major powers, said on Wednesday that they were a "step forward".

The hardline president said Iran considered Geneva talks to be "positive" and they had paved the way for future talks.

He said during last week's discussion in Geneva there had been "better behaviour" from some of the countries taking part.

He further said Iran was ready to buy uranium enriched to the 20 percent purity required by its Tehran research reactor from any country, including the United States.

Thursday's talks with the six powers -- Britain, China, France, Germany, Russia and the United States -- were the first in 15 months. The next round of talks between the two sides would be held end of the month.

Western governments have been seeking reassurances from Tehran that its nuclear programme is entirely peaceful.

"I think these negotiations were a step forward and I hope we proceed with the same trend so we will have constructive cooperation to resolve all outstanding global issues," the state television website quoted Ahmadinejad as saying.

He said Iran was prepared to cooperate with world powers if there was a will to form a "collective and general cooperation on global issues."

"In these negotiations we witnessed better behaviour than in the past from some countries and we noticed that the logic of respect and justice is being established gradually. These talks are good basis for continuation of the negotiations."

Ahmadinejad also backed the one-on-one talks on the sidelines in Geneva between Iran's nuclear negotiator, Saeed Jalili and US delegation head William Burns.

"As far as I know the negotiations of both the sides had a clear and reasonable framework and we approve of this," Ahmadinejad said.

He said that Iran was ready to talk to any country except the "Zionist regime" Israel.

During the Geneva talks, Iran agreed to throw open its second uranium enrichment plant near the central holy city of Qom to UN inspection.

Soon after the talks, UN atomic watchdog chief Mohamed ElBaradei visited Tehran to work out the modalities of the inspection, which is due to take place on October 25.

Iran also offered to send low-enriched uranium abroad so that it could be enriched to higher levels by a third party.

Iran is to hold talks with France, Russia and the United States in Vienna on October 19 to work out the modalities of the third-party enrichment.

"We will buy the fuel from any country that expresses readiness and the United States can be one of the sellers," the official IRNA news agency quoted Ahmadinejad as saying.

"France gives an official proposal, and our experts in the atomic organisation will examine it," he added, when asked about a reported proposal for the enrichment from Paris.

Iran says it needs uranium enriched to 20 percent purity for its internationally supervised research reactor in Tehran.

Uranium enrichment lies at the heart of Western concerns about the Iranian nuclear programme. The sensitive process can produce fuel for civilian nuclear reactors or, in highly extended form, the fissile core of an atomic bomb.

Oil Minister Masoud Mirkazemi meanwhile issued a threat to companies selling petrol to Iran.

"If some companies refuse to sell petrol to us... they will be blacklisted and will never be able to sell petrol to Iran in future," he said.

His warning came a day after US Treasury Undersecretary Stuart Levey told the Senate Banking Committee that if future talks with Iran failed, "the United States would be obliged to turn to strengthened sanctions."

The new round of sanctions being considered by Washington is targeted at global oil firms exporting petrol to Iran.

Iran is OPEC's second largest crude exporter but is heavily dependent on imports of refined petrol to meet its growing needs.