[caption id="attachment_92270" align="alignright" width="195"] Iranian-American Amir Mirza Hekmati, who has been sentenced to death by Iran's Revolutionary Court on the charge of spying for the CIA, stands with Iraqi soldiers in this undated still image taken from video in an undisclosed location made available to Reuters TV on January 9, 2012.[/caption]
DETROIT (AP) -- The sister of a former U.S. Marine imprisoned in Iran said Tuesday that her brother renounces his dual Iranian citizenship and vows to never return to Iran if he's allowed to leave after 3 1/2 years behind bars.


Sarah Hekmati's brother, Amir Hekmati, 31, made the comments in a letter he recently dictated to their mother by phone. Sarah Hekmati said she forwarded it to the office in Pakistan's Washington embassy that represents Iran's U.S. interests and originally granted his Iranian passport and visa before his 2011 trip to visit family.


"It has become very clear to me that those responsible view Iranian-Americans not as citizens or even human beings, but as bargaining chips and tools for propaganda," he wrote in the letter sent to the Iranian Interest Section in Washington. "Considering how little value the Ministry of Intelligence places on my Iranian citizenship and passport, I, too, place little value on them and inform you, effectively that I formally renounce my Iranian citizenship and passport."


Amir Hekmati, who was born in Arizona and raised in Michigan, was arrested in August 2011 while visiting relatives. He was initially convicted of spying and sentenced to death, but that was later overturned and he was sentenced to 10 years in prison on a lesser charge. He and his family deny any wrongdoing, and say his imprisonment has included physical and mental torture and long periods of solitary confinement in a tiny cell.


It's not clear how Hekmati's declaration will be handled by Iranian authorities. His lawyer and government officials could not be reached for comment.


State Department spokeswoman Jen Psaki, speaking to reporters in Washington, said the U.S. has repeatedly "raised his case with Iranian officials and will continue to do so." She added Hekmati's renunciation of his Iranian citizenship "is obviously a personal decision for him to make," and U.S. officials' position remains that Iran "should release him immediately."


Sarah Hekmati said her brother's letter "is just a testament to how frustrated he is" and "a real picture of what he's enduring." Still, she added, that he remains optimistic about the timing of his message as progress is made in negotiations between Iran, the U.S. and five world powers that would limit Tehran's ability to make an atomic weapon while easing punitive economic sanctions on the Islamic Republic.


"He feels like this is a now-or-never opportunity," she said.


By The Associated Press