Ghoochannejhad has linked with his new team-mates as they prepare for their upcoming AFC Cup quarter-final meeting with Indonesia's Persipura Jayapura.
"It was Reza's decision to leave," head coach Bob Peeters told Charlton Athletic's official website.
"He told us that, after the World Cup, he wanted to go to another country and that was Kuwait. If a player wants to leave then it makes it difficult because their mind is already weak from wanting a transfer. That is why we made the decision to allow Reza to leave."
Ghoochannejhad, who scored Iran’s goal in the loss to Bosnia and Herzegovina at the 2014 FIFA World Cup Brazil™, was the second Iranian to play for Charlton after legendary midfielder Karim Bagheri.
Ghoochannejhad also scored the winner against Korea Republic which saw Team Melli qualify for Brazil 2014.
The Mashad-born striker, nicknamed Gucci, moved to the Netherlands at the age of four and has also played for Heerenveen, Go Ahead Eagles, Emmen, Cambuur, as well as Belgian sides St Truiden and Standard Liege.