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In Seoul, more than 50 leaders from around the world have gathered today for the Global Nuclear Security Summit. The talks will focus on a plan to prevent nuclear materials from getting into the hands of terrorists. That initiative was President Obama's, and he is in South Korea. He used the gathering to propose deeper cuts in the U.S. nuclear arsenal. The president also directly addressed the leaders of North Korea, saying they face a choice between peace and further isolation.
NPR's Mike Shuster has more from Seoul.
MIKE SHUSTER, BYLINE: In 2010, President Obama proposed that over four years the world could act to secure most if not all of the plutonium and highly enriched uranium for which there had not been adequate safeguards.
In a speech at Seoul's Hankuk University today, the president praised the program and what it has achieved in just two years.
PRESIDENT BARACK OBAMA: All told, thousands of pounds of nuclear material have been removed from vulnerable sites around the world. This was deadly material that is now secure and can now never be used against a city like Seoul.
SHUSTER: For President Obama, the securing of these dangerous nuclear materials is just one component of a larger goal: ridding the world of nuclear weapons. Citing the current treaty with Russia on limiting deployed strategic nuclear weapons, the president said he believes the current limits are still too high.
OBAMA: We have more nuclear weapons than we need. Even after New START, the United States will still have more than 1,500 deployed nuclear weapons and some 5,000 warheads. I firmly believe that we can ensure the security of the United States and our allies, maintain a strong deterrent against any threat, and still pursue further reductions in our nuclear arsenal.
SHUSTER: The president will soon receive a study of the U.S. nuclear posture with options on how many more nuclear weapons could be cut. And not just deployed strategic weapons. Mr. Obama said he will propose cuts in the thousands of tactical nuclear weapons and stored warheads each side holds when he meets with Vladimir Putin later this spring.
In the long history of arms control treaties between the two countries, Russia and the U.S. have never put these categories of nuclear weapons on the table.
Then President Obama turned to North Korea, and directly addressed the North Korean leaders.
OBAMA: The United States has no hostile intent toward your country. We are committed to peace and we are prepared to take steps to improve relations, which is why we have offered nutritional aid to North Korean mothers and children. But by now it should be clear, your provocations and pursuit of nuclear weapons have not achieved the security you seek. They have undermined it.
SHUSTER: Both President Obama and South Korean President Lee Myung Bak have warned North Korea not to carry out a rocket launch in April. President Lee was speaking through an interpreter at a news conference last night.
PRESIDENT LEE MYUNG BAK: (Through translator) North Korea, if it goes ahead with its plan, will be going straight against its pledges that it made with the international community.
SHUSTER: Still addressing the leaders of North Korea, President Obama said they face a stark choice.
OBAMA: You can continue down the road you are on. But we know where that leads. It leads to more of the same, more broken dreams, more isolation, ever more distance between the people of North Korea and the dignity and the opportunity that they deserve.
SHUSTER: At the news conference last night, President Obama was asked if he had yet taken the measure of North Korea's young new leader, Kim Jong-un. The answer: It's hard to form an impression of him.
OBAMA: The situation in North Korea still appears unsettled. It's not clear exactly who's calling the shots and what their long-term objectives are.
SHUSTER: In any case, President Obama added, what they are doing doesn't work.
Mike Shuster, NPR News, Seoul. Transcript provided by NPR, Copyright NPR.