President Obama and other world leaders are calling for nuclear cuts, to make sure highly enriched uranium (HEU), plutonium and other radioactive substances do not fall into the wrong hands.
They called on countries to; "cut their use and their stocks of highly enriched nuclear fuel to the minimum to help prevent al Qaeda-style militants from obtaining material for atomic bombs."
Russia and The United States set aside their differences over Crimea to endorse the meeting's final statement aimed at enhancing nuclear security around the world, together with other big powers including China, France, Germany and Britain.
The United States petitioned to incorporate U.N. nuclear agency security guidelines into national rules, but Russia, China and several other countries opposed it.
This years nuclear security summit was held at the Hague and was the third since 2010, that President Obama attended. He said; "much headway had been made in the past four years, I think it's important for us not to relax but to accelerate our work over the next two years."
The next nuclear security summit is scheduled to be in The United States, in 2016.