Iranian Navy Commander Habibollah Sayyari announced that the home-made Fateh (Conqueror) submarine will join the Navy in late-November.
The commander went on to note that Iran achieved the technology for building submarines 20 years ago, the country's official IRNA news agency reported on Aug. 18.
Iran has failed to unveil the Fateh submarine despite earlier announced dates.
In 2011, for the first time Iranian officials announced that Fateh would launch operation, then in 2013 Sayyari said that "the submarine will become operational in the current year."
Iran's Defense Minister Brigadier General Hossein Dehqan announced this March that the submarine would probably join the Navy on May 24, the date honoring the anniversary of the liberation of Khorramshahr city during the eight-year war with Iraq.
Dehqan said that the submarine has undergone necessary tests and its faults have been corrected.
Fateh weighs nearly 500 tonnes and it is Iran's newest semi-heavy submarine.
The Iranian media outlets reported that Fateh class subs can operate more than 200 meters below the sea surface for nearly five weeks.
The country has so far launched different classes of home-made advanced submarines including Ghadir, Qaem, Nahang, Tareq and Sina.
Sayyari underlined that Iran is currently mass-producing Ghadir class submarines.