The two-day gathering in Seoul of leaders and high-level representatives from 53 countries and four major organizations around the world ended with a joint declaration, dubbed the "Seoul Communique."
"Nuclear terrorism continues to be one of the most challenging threats to international security," the communique said. "Defeating this threat requires strong national measures and international cooperation, given its potential global political, economic, social and psychological consequences."
The statement called for minimizing the use of weapons-usable, highly enriched uranium by the end of 2013 and set 2014 as a target date for putting into effect an amendment to the Convention for the Physical Protection of Nuclear Materials (CPPNM).
CPPNM is a key international pact that stipulates physical protection of nuclear materials during international transport, lays out a framework for cooperation in the protection, recovery, and return of stolen nuclear material and lists certain serious offenses involving nuclear material. A 2005 amendment, which includes protection for nuclear facilities, has yet to take effect.
The Seoul meeting is a follow-up to the inaugural summit hosted by Obama in Washington in 2010 when leaders focused on strengthening the security of fissile material worldwide and securing against nuclear terrorism.
In Seoul, world leaders, including Obama, Russian President Dmitry Medvedev and Chinese President Hu Jintao assessed accomplishments of commitments made in Washington and laid out more concrete actions to curb the threat of nuclear terrorism and illicit trafficking.
"During the Seoul summit ... new commitments were put forward that will reduce the threat of nuclear terrorism," host South Korean President Lee Myung-bak said during a news conference as chairman.
"I firmly believe these leader-level political consensuses will be embodied through international cooperation and domestic measures of each country," he said.
During the conference, Lee put forth cases of progress one after another that have been made since the Washington summit, including disposal of 480 kilograms of highly enriched uranium by eight countries, an amount enough for 19 nuclear weapons.
Ukraine and Mexico, in particular, accomplished a total "cleanout" of all stockpiles of highly enriched uranium just prior to the Seoul meeting by returning them to Russia and the United States, he said.
In addition, 3,000 nuclear weapons worth of highly enriched uranium has been downgraded to safer, low-enriched uranium in Russia and the U.S. The two nations are also working to implement an agreement that will result in the removal 68 tons of plutonium, enough for 17,000 nuclear weapons, he said.
Other cases of progress included Belgium, France, South Korea and the U.S. announcing a joint project on developing high-density low-enriched uranium fuel to replace highly enriched uranium in research reactors.
The Czech Republic, Mexico and Vietnam converted their research reactors using highly enriched uranium to low-enriched uranium, while Belgium, France, the Netherlands and the U.S. also announced a joint project to produce medical isotopes without the use of highly enriched uranium by 2015.
Noting Japan's nuclear disaster last year, the communique also called for "the nexus between nuclear security and nuclear safety."
"We consider that sustained efforts are required to address the issue of nuclear safety and security in a coherent manner that will help ensure the safe and secure peaceful uses of nuclear energy," it said.
In the aftermath of Japan's Fukushima nuclear disaster, calls have grown for the U.N. nuclear watchdog, the International Atomic Energy Agency (IAEA), to carry out more stringent inspections and for better cooperation and crisis management among nuclear regulators around the world.
The potential threat of nuclear terrorism was highlighted by the Fukushima disaster because it showcased the extent of potential damage if terrorists were to sabotage key systems of a nuclear power plant such as a power supply or cooling system, experts said.
The document reaffirmed the key role of the IAEA.
"We welcome the intent by the IAEA to continue to lead efforts to assist states" to effectively prevent nuclear terrorism and ensure the safety of atomic energy.
During the news conference, Lee said it will be difficult for North Korea to transfer nuclear material out of its borders if countries around the world follow through with measures discussed during the just-ended international conference on nuclear security.
"Unlike in the past, it will be difficult for North Korea" to transfer nuclear material beyond its borders "if an international monitoring system gets into operation," he told the conference.
Lee also said world leaders raised North Korea's planned rocket launch during the conference.
"Though it was discussed during bilateral summits, many leaders also raised the issue during the main meeting as well," Lee told the conference. "I think North Korea will be affected psychologically by these efforts to keep nuclear material from falling into the hands of dangerous people."
Lee stressed that the rocket launch is a "head-on challenge" to the international community.
Lee also said that not only the United States, but also Russia and even the "Chinese representative" pointed out during bilateral summits with him that the rocket launch is not desirable at a time when Pyongyang should care about improving the lives of its people.
A third summit will be held in the Netherlands in 2014.
Source: Yonhap News Agency