and president obama at the summit. the largest gathering since 1945 and the founding of the united nations. sitting down with a handful of delegations today sent of state hillary clinton made the talk show rounds setting the stage for the conference tomorrow. we often say that the threat of nuclear war as we used to think about it for the coal war has actually decreased, but the threat of nuclear terrorism has increased. >> julie kirtz is live at the white house with the latest. >> hi, juliet. even before the summit fieshl gets underway, president obama saying he feels good about the sense of urgency he sees among all the world leaders gathering here in washington. today, pre-summit, the president held a series of one-on-one meetings with world leaders at blair house, across from the white house. talking with leaders of india and pakistan two countries with nuclear programs. it was during his session with the president of south africa, he spoke to reporters and