Despite strained US-Iranian ties, US Secretary of State John Kerry has praised Tehran for being “helpful” in the mission to stamp out the Islamic State terror group in Iraq.Asked if Iran’s influence in Iraq was “more helpful or more harmful” at the Aspen Ideas Festival in Colorado, Kerry gave an unexpected response.“Look, we have challenges with Iran as everybody knows and we are working on those challenges,” RT online quoted Kerry as saying. “But I can tell you that Iran in Iraq has been in certain ways helpful, and they clearly are focused on IS, and so we have a common interest, actually."Islamic State’s power has been on the wane in Iraq, particularly in the volatile Anbar province, where a coordinated effort by Iraqi ground forces and American air power has weakened it. The Americans believe that cooperation between Tehran and Washington can only go as far as fighting the IS, each for its own ends. The US has also accused Iran of helping the Americans in Iraq in order to quietly secure a route to its allies in Syria.The Obama Administration is currently split on some key issues regarding Tehran. The US Treasury and State departments are at odds over just how much financial support Iran should be entitled to following the recent landmark nuclear deal.