Iran and six major powers have agreed to meet in Geneva next month for further talks on resolving the standoff with Tehran on its nuclear programme.

US and Iranian officials emerged upbeat on Thursday from a meeting on Iran's nuclear programme, but both sides sounded a cautionary note, with the US saying there was more work to do and Iran insisting on quick sanctions relief.

Mohammad Javad Zarif, Iran's foreign minister, said after talks with US Secretary of State John Kerry following the meeting that the key world powers had agreed to fast-track negotiations over the programme to within a year.

However, Kerry said later that the US would not lift sanctions on Iran until it showed it was not pursuing a nuclear-weapons capability.

President Hassan Rouhani said Iran was committed to negotiate on its nuclear programme in "good faith" after the highest-level talks yet held with world powers.

"We are fully prepared to seriously engage in the process toward a negotiated and mutually agreeable settlement and do so in good faith and with a business-like mind," Rouhani told a forum in New York.

One meeting and a change in tone, which was welcome, doesn't answer those questions yet and there is a lot of work to be done US Secretary of State John Kerry.

Catherine Ashton, the European Union's foreign policy chief, said that the UN meeting with Iran officials on Thursday had been a very positive first step in resolving the dispute.

"We had a discussion about how we would go forward with an ambitious timeframe to see whether we can make progress quickly," Ashton said after the meeting.

The meeting took place on the sidelines of the UN General Assembly in New York and included Iranian Foreign Minister Mohammad Javad Zarif and counterparts from the US, France, Russia, China and Germany.

Zarif said after taking part in bilateral talks with Kerry, in one of the highest level contacts between the two foes since the 1979 Islamic Revolution, that they had stressed "the need to continue these discussions to give it the political impetus that it requires and to hopefully to reach a conclusion within a reasonable time."

"We agreed to jump-start the process so that we could move forward with a view to agreeing first on the perimeters of the end game," the foreign minister said. "And move towards finalising it hopefully within a year's time.

"I thought I was too ambitious, bordering on naivete. But I saw that some of my colleagues were even more ambitious and wanted to do it faster.''

Kerry said he was pleased with the new positive tone from Iran.

Ambitious plan

The talks aim to pave the way for the first round of substantive nuclear negotiations since April [Getty Images]

"Needless to say, one meeting and a change in tone, which was welcome, doesn't answer those questions yet and there is a lot of work to be done," Kerry said after the talks.

He later said in an interview with the CBS show 60 Minutes on Thursday that one concrete step Iran could take to show it was serious about not seeking nuclear arms would be to open up its Fordow uranium enrichment facility to UN inspectors.

"The United States is not going to lift the sanctions until it is clear that a very verifiable, accountable, transparent

process is in place, whereby we know exactly what Iran is going be doing with its programme," Kerry said.

Ashton said the Geneva meeting on October 15 to 16 would "carry on from today's meeting and hopefully move this process forward."

Meanwhile, Iran's new envoy to the International Atomic Energy Agency (IAEA) said on Friday that scheduled talks would take place later in the day in Vienna, marking the first such meeting since the new Iranian government took power.