Video: Barack Obama urges North Korea to 'pursue peace' Barack Obama vowed on Monday to pursue further strategic arms reductions with Russia as part of his broader nuclear disarmament agenda even as he issued stern warnings to North Korea and Iran in their nuclear standoffs with the West. Speaking ahead of a global nuclear security summit in Seoul, Obama held out the prospect of new cuts in the U.S. nuclear arsenal as he sought to rally world leaders for additional concrete steps against the threat of nuclear terrorism. "But even as we have more work to do, we can already say with confidence that we have more nuclear weapons than we need," Obama said in a speech at South Korea's Hankuk University, pledging a new arms-control push with incoming Russian president Vladimir Putin when they meet in May. Obama also used his speech to call on North Korea, which plans a rocket launch next month, to curb its nuclear ambitions or else face further international isolation. To the leaders of Pyongyang I say this, the choice before you, this is the decision you must make. Today we say, Pyongyang, have the courage to pursue peace and give a better life to the people of North Korea," he said, directing his comments at the leadership of the secretive state. South Korean President Lee Myung-bak urged his Chinese counterpart, Hu Jintao to try to persuade the North to cancel next month's rocket launch, which Pyongyang says is merely to send a satellite into space.