Lebanon is calling on Iran to use the upcoming holy month of Ramadan to grant amnesty to a Lebanese citizen who is also a U.S. resident imprisoned there for more than three years.

The appeal for the release of Nizar Zakka came Friday in a letter sent by Lebanon's Foreign Minister to his Iranian counterpart. The letter was delivered to the Iranian ambassador to Lebanon.

Zakka, a U.S. permanent resident, is an advocate for internet freedom and has done some work for the U.S. government. He has been imprisoned in Iran since his arrest in September 2015 while attending a state-sponsored conference. He was sentenced to 10 years on espionage-related charges.

In 2017, Zakka went on a hunger strike for over a month calling for his release.