The White House will host an on-the-record press conference call to preview the Nuclear Security Summit in Washington, DC.  The Summit will convene delegations from more than 50 nations that will continue discussion on the evolving threat and highlight steps that can be taken together to minimize the use of highly-enriched uranium, secure vulnerable materials, counter nuclear smuggling and deter, detect, and disrupt attempts at nuclear terrorism. In addition, this year's Summit includes a special session that will focus leaders on the threat of groups like ISIL attacking urban areas across the globe.  The United States seeks a strengthened global nuclear security architecture that is comprehensive, is based on international standards, builds confidence in nations’ nuclear security implementation, and results in declining global stocks of nuclear weapons-usable materials.