Nuclear program of Iran
U.S. President Obama reportedly sent a letter dated 20 April 2010 to President Lula of Brazil, in which he outlined a proposal of fuel swap. While expressing skepticism that the Iranians would now be willing to accept such a deal, having provided "no credible explanation" for the previous deal's rejection, President Obama wrote "For us, Iran’s agreement to transfer 1,200 kg of Iran’s low enriched uranium (LEU) out of the country would build confidence and reduce regional tensions by substantially reducing Iran’s LEU stockpile." Turkish Prime Minister Recep Tayyip Erdogan received a similar letter. A senior U.S. official told the "Washington Post" that the letter was a response to Iran's desire to ship out its uranium piecemeal, rather than in a single batch, and that during "multiple conversations" U.S. officials made clear that Iran should also cease 20% enrichment; however, the official stated "there was no president-to-president letter laying out those broader concerns".
Politics of Iran
The Supreme Leader of Iran is the head of state and highest ranking political and religious authority in the Islamic Republic of Iran (above the President). The armed forces, judicial system, state television, and other key governmental organizations are under the control of the Supreme Leader. There have been only two Supreme Leaders since the founding of the Islamic Republic, and the current leader (Ali Khamenei), has been in power since 1989. His powers extend to issuing decrees and making final decisions on the economy, environment, foreign policy, education, national planning of population growth, 
the amount of transparency in elections in Iran, and who is to be fired and reinstated in the Presidential cabinet.