The university said separately that it is 'very distressed' by the charges leveled against Xiyue Wang while he was carrying out scholarly research in the Islamic Republic. It has been working with Wang's family, the U.S. government, lawyers and others to secure his release, it added.
'His family and the university are distressed at his continued imprisonment and are hopeful that he will be released after his case is heard by the appellate authorities in Tehran,'' the university said.
Iran's judiciary announced Wang's conviction during a routine press conference on Sunday; he was not previously known to be among the handful of Americans detained in Iran.
An article posted on Mizan Online, a website affiliated with the judiciary, said 37-year-old Wang was born in Beijing and entered Iran as a researcher. It described him as fluent in Persian.
He was arrested on Aug. 8, 2016 and is accused of passing confidential information about Iran to the U.S. State Department, Princeton's Sharmin and Bijan Mossavar-Rahmani Center for Iran and Persian Gulf Studies, the Harvard Kennedy School and the British Institute of Persian Studies, according to the website. It alleged he recorded some 4,500 pages of digital documents.
Princeton University professor Stephen Kotkin, who has served as Wang's doctoral adviser, defended him in an email to The Associated Press.
'Xiyue Wang is a remarkable, linguistically gifted graduate student,' he wrote. 'He is innocent of all the charges.'
The documents Wang collected were 100 years old, Kotkin said, adding that Wang 'has told me often of his exhilaration at the exquisiteness and depth of Persian civilization.'
In its statement, Princeton said Wang was arrested while conducting research on the 1794-1925 Qajar dynasty for his doctorate in late 19th and early 20th century Eurasian history.
A photo of Wang on Princeton's history department shows him posing under a plaque at the entrance of China's official Xinhua News Agency's bureau in Kabul, Afghanistan.
A short bio on the Princeton in Asia website said Wang had been a fellow in Hong Kong in 2008-2009, had completed a bachelor's degree in South Asian studies at the University of Washington and did Russian and Eurasian studies at Harvard.
'For better or worse, he still can't tell you what exactly he has been studying in the many years that have passed,' the site said. 'What he does know is that his dream is to walk the ancient Silk Road from Xi'an to Rome one day.'
The U.S. State Department has not provided details on the case but called on Tehran to immediately release 'all U.S. citizens unjustly detained in Iran.' The U.S. does not maintain formal diplomatic relations with Tehran and warns its citizens traveling there that they risk arrest or being barred from leaving Iran.
'The Iranian regime continues to detain U.S. citizens and other foreigners on fabricated national-security related changes,' it said in a statement to the AP.
Other Americans who remain in Iranian custody include Iranian-American art gallery manager Karan Vafadari, who was detained along with his Iranian wife last year. They have yet to be convicted of a crime.
Iranian-American businessman Siamak Namazi and his 81-year-old father, Baquer Namazi, are each serving 10-year sentences for 'cooperating with the hostile American government.'
Another Iranian-American, Robin Shahini, was released on bail last year after staging a weeks-long hunger strike while serving an 18-year prison sentence for 'collaboration with a hostile government.' He is believed to still be in Iran.
Former FBI agent Robert Levinson, who vanished in Iran in 2007 while on an unauthorized CIA mission, remains unaccounted for.
Also in an Iranian prison is Nizar Zakka, a U.S. permanent resident from Lebanon who advocates for internet freedom. He lives in Washington D.C. and has done work for the U.S. government. He was sentenced to 10 years behind bars last year after being accused of espionage-related charges.