Iran wants to work with other powers in the Middle East to promote peace following last month's nuclear deal, Vice-President Masumeh Ebtekar says.
In an interview with the BBC, Ms Ebtekar stressed that Iran had a right to defend itself, but that it had no intention of dominating the region.
Her country hoped to regain the trust of neighbouring states and co-operate to counter extremist groups, she added.
Iran has been accused of fomenting unrest throughout the Middle East.
It provides money and weapons to Syrian President Bashar al-Assad and the militant Lebanese Shia Islamist group Hezbollah, and allegedly backs Yemen's rebel Zaidi Shia Houthi movement.
But it has also played a major role in the battle against jihadist militants from Islamic State (IS) in Iraq in the past year, mobilising Shia militias and sending advisers to help the Iraqi military.
'New era'
Vice-President Ebtekar spoke to the BBC's Kim Ghattas during a week-long assignment in Iran - the longest time a BBC correspondent has been granted permission to report from there since June 2009, when the re-election of President Mahmoud Ahmadinejad sparked mass protests.

In the interview, Ms Ebtekar said the recent deal that saw Iran agree to limit its sensitive nuclear activities in return for the end of crippling sanctions represented a "step forward" for the whole world.
"It means a new era of working with the world in terms of different dimensions of trade, cultural exchanges," she explained. "It means that Iran is going to be a more prominent player in this part of the world."

By BBC News