Mr Mottaki spoke to diplomats in Havana at the Non-Aligned Movement conference on Wednesday and hoped that talks would “clarify outstanding issues”.
In a closed-door foreign ministers' meeting delegates confirmed that Mr Mottaki, in a speech obtained by AFP, said that Iran "has continued its cooperation with the agency (International Atomic Energy Agency) to facilitate the resolution of the outstanding issues related to its peaceful nuclear activities within the framework of the agency."
The Iranian chief diplomat said NAM colleagues had voiced solidarity with Tehran on the nuclear issue.
"NAM through this support has rejected the efforts by some to limit and restrict the inalienable right of states to develop and use nuclear energy for peaceful purposes," Mottaki added in his speech.
Egyptian Foreign Minister Ahmed Aboul Gheit told reporters "Iran is allowed to possess nuclear technology. The NPT offers them the right, for peaceful uses."
He added that the NAM had received "very strong assurances that the objective is not nuclear weapons."
"We have to believe them until it is established otherwise," Mr Gheit said. "The important thing for the world community is to convince Israel to relinquish its reliance on nuclear weapons."
Rice signals sanctions
In Washington, Secretary of State Condoleezza Rice said foreign ministers from the six major powers involved in the nucelar talks will meet soon in New York to discuss imposing sanctions against Tehran.
Ms Rice will be travelling to New York next week for talks on the sidelines of the United Nations General Assembly.
She said this would be the opportunity to press ahead with the sanctions if Iran continues to reject demands it freeze its suspected nuclear weapons program.
In Vienna, the United States and Europe earlier urged Iran to choose negotiations over UN sanctions, even as EU-Iran talks on Tehran's refusal to heed demands that it suspend uranium enrichment stalled.
A meeting planned for Thursday between EU foreign policy chief Javier Solana and Iran's top nuclear negotiator Ali Larijani was postponed and only their aides will meet in Paris, Mr Solana's spokeswoman said.
Mr Solana and Mr Larijani had held talks dubbed "constructive" over the weekend in Vienna, raising hopes that they might lead to formal negotiations between Iran and six nations seeking a way out of the nuclear crisis.
At a meeting in Vienna of the IAEA, the UN nuclear watchdog, US ambassador Gregory Schulte urged Tehran to "make the right choice and avoid the consequences" of UN action should it continue to refuse to halt its enrichment activities.
The United States, which charges that Iran is hiding secret work to make nuclear weapons, is pushing for UN sanctions against Iran for failing to honor a UN resolution that set an August 31 deadline for Tehran to halt the enrichment activity. Iran says its program is for peaceful energy ends only.