Donald Trump’s war with Iran is likely to drag on for another six months, Leon Panetta, the former US defense secretary, has warned, as the US president struggles to find his way out of the controversial conflict.

Panetta declared in an interview that the war with Iran – launched by Trump over six months ago – risks becoming another “forever war in the Middle East”, with no clear end in sight.

“It’s no mystery that the United States and Iran are caught in a terrible stalemate, in which there really are very few options available to bring this war to an end,” said Panetta, who also served as CIA director under Barack Obama, suggesting the conflict is on course to become “another failed war” in the Middle East “like Iraq and Afghanistan”.