Secretary-General's remarks at the opening session of the Nuclear Security Summit

I thank the Government of the Netherlands for hosting this third Nuclear Security Summit. Nuclear security remains a pressing concern, not least the risk of nuclear terrorism. The primary responsibility for preventing non-state actors and terrorists from acquiring the most devastating weapons known to humanity lies with national governments. But international cooperation and assistance are indispensable. Important challenges include strengthening nuclear security implementation and building a culture of nuclear security. I see three areas where the United Nations has an important role to play.