The world powers are “closer than ever” to clinch a “good comprehensive deal” with Iran that will prevent it from obtaining a nuclear weapon but some key issues still remain unresolved, US Secretary of State John Kerry has said. “The United States and our P5+1 partners have come together with Iran around a series of parameters that, if finalised and implemented, will close off all of Iran’s possible pathways to the nuclear material required for a nuclear weapon, and give the international community the confidence that it needs to know that Iran’s nuclear programme is indeed exclusively peaceful,” Kerry said at the 2015 Nuclear Nonproliferation Treaty Review Conference on Monday. Kerry, however, told the international community that the “hard work is far from over and some key issues remain unresolved.” Still the P5+1, comprising the US, the UK, Germany, France, Russia and China facilitated by the European Union, are “closer than ever to the good comprehensive deal that we have been seeking. And if we can get there, the entire world will be safer,” he said here.