Iran wants to release all of its citizens who are held in the United States in parallel with talks aimed at reviving the 2015 nuclear deal currently taking place in the Austrian capital, Vienna.
Government spokesman Ali Rabiei hinted at the possibility of another prisoner exchange between the Islamic Republic and the United States, saying "the idea of exchanging prisoners has always been on the agenda".
He added that the Iranian prisoners should be released due to "humanitarian concerns".
Rabiei did not provide more details about the detainees, adding that disclosing their names might harm them. However, he pointed out that their number is "greater than the number of American prisoners in Iran".
In 2019, Iran released a Princeton University graduate student who had been held for three years on charges of espionage, while the United States freed an Iranian stem-cell researcher who faced charges of violating US sanctions against Tehran.