Tehran, Oct 22 (IANS): The remaining steps in the talks over Iran's nuclear programme are "crucial and difficult", Iranian foreign ministry spokeswoman Marzieh Afkham said here on Wednesday.

"We are at the last stage of nuclear negotiations which are very important, crucial and difficult. Major part of the course (for a comprehensive agreement) has been taken and what is remaining is rough and determining," Xinhua quoted Afkham as telling reporters in her weekly press briefing.

All the sides were trying to achieve results within the coming days so that the Nov 24 deadline was met, she said.

The Iranian spokeswoman stressed that extending the deadline for the second time was not on the agenda of the ongoing talks between Iran and the world powers.

In July, Iran and the P5 1 group -- the US, Britain, France, Russia and China plus Germany -- agreed to extend negotiations over Iran's controversial nuclear programme for another four months till Nov 24 as they could not narrow down the significant gaps on core issues during the past six months.

After the deal between Iran and the P5 1 group Nov 24 last year, both sides have held several rounds of talks to work out a final agreement aimed at ending the long-standing dispute over Tehran's nuclear programme.

The new round of negotiations at the expert level resumed in the Austrian capital of Vienna Wednesday. The anti-Iran sanctions and the country's uranium enrichment capacity are two main key differences between Iran and the P5 1 group.