As world leaders are gathering in the Netherlands for the third summit on nuclear security, they were urged to establish an effective mechanism on the control of nuclear material. The third Nuclear Security Summit, to be held on Monday and Tuesday in The Hague, will bring together leaders and delegates from 53 countries and international organizations. According to the organizing committee, three main issues are to be discussed at the summit: reducing the amount of dangerous nuclear material in the world, improving security of existing material and stepping up international cooperation. Many countries have made valuable contributions and commitments to nuclear security in the past four years, but those efforts were not enough to establish an effective management and control mechanism on the security of nuclear materials, said Deepti Choubey, senior director for Nuclear and Bio-Security and the Nuclear Threat Initiative organization. "The materials we are talking about are highly-enriched uranium and plutonium," Piet de Klerk, chief negotiator of the nuclear summit explained. The materials, which can be used to make nuclear weapons, are fissile and could split more atoms and trigger a chain reaction commonly known as a nuclear explosion. "Plutonium is also very dangerous if ingested," the Dutch chief negotiator added. "It is easy to protect against its radiation, but even a small amount of plutonium in your body, or polonium for that matter, can cause irreparable damage." Despite the danger of nuclear materials, creating a real nuclear bomb is very complicated, according to Dick Schoof, chief of the Dutch National Coordinator for Security and Counterterrorism. "But the concern lies with all kinds of other radioactive material. If you combine enough of this material with ordinary explosives you cannot make a nuclear bomb, but you can make a 'dirty' bomb and radioactively contaminate a large area. That is a huge threat at the moment," the official said. Over 100 times a year, nuclear or radioactive material gets lost or stolen and appears somewhere else in the world, according to figures from the International Atomic Energy Agency (IAEA). Between 1993 and 2012, there were 2,331 reports of such findings. The IAEA assumes that in reality, there are even more incidents because countries report on a voluntary basis. Though these reports are not about material falling into the hands of terrorists, they show radioactive and nuclear materials are not as secure as they should be. Against such background, it is urgent to reduce the amount of dangerous nuclear material in the world and improve the security of existing material. "Every state is responsible for the nuclear material on its territory," the chief negotiator Piet de Klerk said, calling for international cooperation to secure nuclear material safety. China has been active in combating events threatening the safety of nuclear material and facilities. The country has built a demonstration center on nuclear security technology and helped train technicians from other countries. Chinese President Xi Jinping, who is now on a state visit to the Netherlands and will attend the summit, is expected to present China's view on nuclear security. Speaking of the expectations for the summit, Choubey suggested that unified criteria and optimal measures be applied globally and that all countries should strengthen monitoring of nuclear materials to reduce risks. The nuclear summit, initiated by U.S. President Barack Obama, who hosted the first one in Washington in 2010, aims to prevent nuclear terrorism around the globe. World leaders were expected to adopt a declaration at their two-day event this time.