The US is to host a meeting of major world powers to discuss plans for a new round of sanctions against Iran over its contentious nuclear programme.
Iran has agreed to co-operate with international inspectors
The five permanent members of the UN Security Council, plus Germany, will meet in Washington on 21 September.
Iran denies accusations it is seeking to develop nuclear weapons and has recently renewed co-operation with the UN's nuclear watchdog, the IAEA.
But it refuses Western demands to end its programme of uranium enrichment.
Speaking on Wednesday after a renewed call from the European Union for an end to enrichment, Tehran's chief nuclear negotiator said only "new initiatives" would lead to a diplomatic breakthrough.
"We say that new possibilities should be explored... and we should not go back on the past," Ali Larijani said, referring to a previous temporary suspension of enrichment.
The Security Council has already imposed two rounds of sanctions on Iran for failing to suspend uranium enrichment.
'No need' for bomb
In an interview with British television Iran's president, Mahmood Ahmadinejad, asked why Iran should stop an activity in which the United States and Britain were also engaged.
He also reiterated that Iran had no desire to build a nuclear bomb, which he said would not be in its political interests.
"The main problem is the enmity of America towards Iran. From the beginning we said that everything should be solved by the (International Atomic Energy) Agency. We do not need a bomb," he told Channel 4 News.
Iran resumed co-operation with the IAEA (International Atomic Energy Agency) in August after agreeing a plan to clear up unresolved issues relating to its past nuclear activities.
But, referring to the continued threat of sanctions, Iran's ambassador to the IAEA, Ali Ashgar Soltanieh, denounced continuing interference by the West.
"Politically motivated interference will definitely jeopardise this new constructive trend," he said.
"Therefore, we expect the international community to be aware of this fact that now Iran has done its part and now we expect the others want to show their political goodwill."
UN Secretary General Ban Ki-moon has also called for Iran to suspend its enrichment work, not simply co-operate with UN inspectors.
And a number of Western diplomats have criticised the IAEA plan, accusing Iran of trying to delay the imposition of further UN sanctions while increasing its nuclear capabilities.
Enriched uranium can be used for civilian nuclear power stations but can also provide fissile material for nuclear bombs.