"The only way to resolve Iran's nuclear issue is to resume negotiations without any preconditions and to enhance cooperation with the involvement of all relevant parties," said a declaration issued at the end of an OIC foreign ministers' meeting in Baku, capital of Azerbaijan.

The foreign ministers also said that all issues on nuclear safeguards and verification, including those of Iran, should be resolved within the framework of the Vienna-based UN nuclear watchdog, the International Atomic Energy Agency.

Washington has accused Iran of secretly developing nuclear weapons under a civilian front, a charge denied by Tehran, which says its nuclear program is only aimed at generating power.

Earlier this month, Iran received an international package of incentives aimed at persuading it to halt nuclear enrichment. Tehran is yet to give a formal response.

The offer, details of which have not been made public, was backed by the five permanent members of the UN Security Council and Germany. It was presented to Iran by European Union foreign policy chief Javier Solana.

Iranian Foreign Minister Manouchehr Mottaki said on Tuesday in Baku that his country was ready to enter talks with European countries without any preconditions.

"Talks could take place before we give an eventual answer. A number of issues and doubts in the package of proposals need to be clarified," Mottaki said.

"That is why there is a need to start negotiations between Iran and other countries, of course without any preconditions, in order to achieve a rapprochement of the parties," he said.