Obama reiterated his position on theIrannuclear issue after talks with Turkish Prime Minister Tayyip Erdogan on the eve of a nuclear security summit inSeoul.

"I believe there is a window of time to solve this diplomatically but that window is closing," Obama told reporters.

He has pressedIsraelto hold off on any attack onIran's nuclear sites to give sanctions and diplomacy time to work. But he has said military action remains an option if all else fails.