Six world power have never been so close to a deal with Iran that would resolve the decade-long nuclear standoff once and for all, but the final phase of the negotiations will be the hardest, Germany's foreign minister said on Thursday."We have never been so close to a deal as now. But the truth is that the final phase of the talks that lay before us is probably the most difficult," Foreign Minister Frank-Walter Steinmeier told reporters after meeting Iran's President Hassan Rouhani on the sidelines of the UN General Assembly."Now is the time to end this conflict. I hope that Iran ... in view of the situation in the world and the situation in the Middle East, knows and senses that a collapse of the talks now is not permissible."