Iran's president says a deal on his country's nuclear fuel is a one-off opportunity.

Iranian President Mahmoud Ahmadinejad, during a news conference in Istanbul, Turkey on Tuesday. Ahmadinejad said a nuclear swap deal brokered by Turkey and Brazil is a one-time opportunity that should not be missed. (Burhan Ozbilici/Associated Press)Speaking in Istanbul, where he is attending an Asian security conference, Mahmoud Ahmadinejad said new sanctions against his country would be a mistake.

Last month in Tehran, Turkey and Brazil brokered the deal, which would see Iran deposit 1,200 kilograms of low-enriched uranium in Turkey in exchange for 120 kg of fuel for its research reactor.

That deal was meant to curtail Iran's ability to produce highly enriched uranium, which can be used in nuclear weapons.

"The meeting in Tehran created an opportunity for the U.S. administration and for its allies, and we still hope that they will be able to use this opportunity," Ahmadinejad said in reference about the swap deal. "We say that this opportunity will not be repeated."

"Unless their policies change, Obama will be the first to lose, and then the U.S. government," he said.

Western nations are suspicious of Iran's nuclear intentions, and the U.S. government has criticized the deal brokered by Turkey and Brazil as not doing enough to prevent Iran from enriching uranium.

The United Nations Security Council is due to vote soon on new sanctions against Iran.

With files from The Associated Press