At least four Iranian-Americans are known to be detained or imprisoned in Iran: Baquer Namazi, 80, and his son Siamak are serving 10-year sentences in Tehran's notorious Evin prison and are believed to be in ill health.
Iran has sentenced a Chinese-born American dual national to 10 years in jail, accusing him of spying for the U.S. government.
This person, who was directly guided by the U.S., was entered the country "under special conditions", he said, adding that he was arrested due to the vigilance of Iranian intelligence ministry forces.
The U.S. State Department accused Iran of fabricating national security-related charges to detain Americans and other foreigners.
Wang was arrested in July 2016 as he was trying to leave Iran "after he became nervous about his situation", Mizan said.
The official news report from Mizan said that Wang was sentenced as part of an "infiltration project" that involved gathering "confidential articles" to send to the U.S. Department of State and Western universities.
The Iranian official further said that the issued sentence is tentative and can be appealed for a review.
"We call for the immediate release of all u.s. citizens unjustly detained in Iran so that they can return to their families", says the text.
AFP 2017 Mahmood Hosseini /TASNIM NEWSUS Expands Anti Iran Sanctions Over Ballistic Missile Program Chinese Turkish Companies on the List
Xiyue Wang had been arrested last August, with a spokesman for the Iranian state judiciary announcing on Sunday that the sentence had been handed down.
It has been working with Wang's family, the US government, lawyers and others to secure his release, it said, adding that it hopes he will be released on appeal.
Princeton identified the man as Xiyue Wang, a fourth year graduate student of history at the university.
The brother of President Hassan Rouhani has been detained and an unnamed United States citizen sentenced to 10 years behind bars for "infiltrating" the country.
Tehran's nuclear deal with world powers in 2015 brought the country relief from global sanctions in exchange for limits on its atomic energy program.
"Before his arrest he was able to digitally archive 4,500 pages of the country's documents while under covert surveillance", the agency added.
Most are thought to be Iranians who hold another passport from Europe or the United States. While remaining US sanctions have slowed economic gains promised by the accord, signs that global interest in Iran is growing have disturbed some hardliners, who foresee their power waning.
Federal Bureau of Investigation agent Robert Levinson, who vanished in Iran in 2007 while on an unauthorized Central Intelligence Agency mission is still missing.