WASHINGTON, April 13 (Xinhua) -- Leaders and representatives from 47 states ended a nuclear security summit here Tuesday, pledging to prevent terrorists from obtaining nuclear weapons by securing vulnerable nuclear materials around the world in four years.
"We made real progress in building a safer world," U.S. President Barack Obama said at a press conference after the meeting.
Part of the progress Obama was referring to was two documents adopted by the leaders: the first was a 12-point communique vowing commitment to lock up loose nuclear materials, a goal he outlined in a speech in Czech capital Prague one year ago; the second was a work plan that outlines specific steps to realize the goal.
"We welcome and join President Obama's call to secure all vulnerable nuclear material in four years, as we work together to enhance nuclear security," reads the communique.
Leaders from China, Russia, France, Germany, Brazil and Japan were among participants at the summit, making it the largest gathering of world leaders in Washington in more than 60 years.
Heads of the United Nations, the International Atomic Energy Agency (IAEA) and the European Council also joined the leaders in their discussions on Monday and Tuesday.
The summit was convened based on the understanding that "two decades after the end of the Cold War... the risk of a nuclear confrontation between nations has gone down, but the risk of nuclear attack has gone up," because "it is increasingly clear that the danger of nuclear terrorism is one of the greatest threats to global security," according to Obama.
John Brennan, Obama's deputy national security advisor for counterterrorism and homeland security, said before the summit that al-Qaeda has been actively seeking nuclear weapons for the past 15 years.
Countries responded to that assessment not only by adopting the communique and the work plan, but also with "meaningful steps that can be implemented right now," Obama said.
Right before the summit kicked off on Monday, Ukrainian President Victor Yanukovich pledged his government would scrap all its stockpile of highly enriched uranium by 2012. Canadian Prime Minister Stephen Harper also announced Monday his government intended to send hundreds of kilograms of spent highly enriched uranium back to the United States.
Russia, for its part, signed with the United States a plutonium disposition protocol, with the aim to eliminate "excess weapons-grade plutonium from defense programs."
During the summit, Argentina and Mexico also made arrangements with the United States and other parties aimed at enhancing nuclear security.
The leaders agreed to enhance the role of the IAEA, reaffirming its "essential role" in international nuclear security framework, promising to ensure that the UN nuclear watchdog "continues to have the appropriate structure, resources and expertise needed to carry out its mandated nuclear security activities."
Anita Nilsson, director of IAEA Office of Nuclear Security, told Xinhua in an interview on the fringes of the summit that the IAEA has programs to give assistance to countries interested in improving the security at facilities where nuclear material is stored, to "lock it up in a better way."
Apart from the IAEA, leaders "support the objectives of international nuclear security instruments," which include the Convention on the Physical Protection of Nuclear Material, and the International Convention for the Suppression of Acts of Nuclear Terrorism, as essential elements of the global nuclear security architecture.
The leaders "come together with the same intention of shaping a system which is both suitable for today in dealing with the legacy of the past, and is sustainable enough to carry its way into the future," said Nilsson.
One of the summit's surprises is that it won't be a stand-alone event. South Korea has agreed to host the next summit in 2012.
"I hope to see all of you in Korea," said South Korean President Lee Myung-bak to world leaders.