The lawyer of a Lebanese man held in Iran since 2015 says his client will be released in the "next few days."

Majed Dimashkiyeh told The Associated Press Monday that Nizar Zakka's expected release comes after mediations by top Lebanese officials including President Michel Aoun and Prime Minister Saad Hariri.

Zakka, who has permanent U.S. residency, went missing in 2015, during his fifth trip to Iran. Two weeks later, Iranian state TV reported that he was in custody and suspected of having "deep links" to U.S. intelligence services.

Zakka was sentenced to 10 years in prison in September 2016 and handed a $4.2 million fine after a security court convicted him of espionage.

Members of the U.S. House of Representatives issued a resolution two years ago calling for Zakka's release.