Former CIA Director David Petraeus told BBC that "forced regime change in Iran will be problematic, but the US will still achieve significant results in the current operation."

"The problem is that it is quite difficult to take control of a country if hundreds of thousands of armed and organized members of the regime's security forces remain in it," he said on BBC Radio 4.

Petraeus also noted that US President Donald Trump has already made clear there will be no ground operation in Iran, adding that "even without regime change in Iran, the US will achieve important objectives."

David Petraeus commanded US and NATO forces in Iraq and Afghanistan and served as CIA Director in 2011–2012.