"Our defense doctrine is that we will not initiate any attack, and that is a written one," Rear Admiral Shamkhani was quoted as saying in Tuesday's governmental Iran newspaper.
"In the past 25 years we never initiated any attack. Every time it was the other side who launched an offensive," he added.
In an interview with Al-Jazeera TV on Wednesday, during which the minister's comments were dubbed into Arabic, Shamkhani said "we will not sit to wait for what others will do to us" when asked if Iran would respond to a US attack on its nuclear facilities.
Tehran has since said the remarks were misinterpreted and "altered".
Recent weeks have seen a mounting war of words between Israel and Iran in recent weeks focusing on Iran's nuclear programme.
Iran insists that the programme, centered on the construction of a nuclear power plant at Bushehr, is purely peaceful but the United States and Israel in particular fear it conceals efforts to develop atomic weapons.