Six way (the two Koreas, the U.S., China, Russia and Japan) talks over North Korea's nuclear weapons program ended without any result. The U.S. demands that any deal include intrusive inspections to make sure that North Korea is not cheating (as it did after the 1994 deal.) North Korea refuses inspections like this and wants the United States to sign a non-aggression agreement and pay billions of dollars on the promise that North Korea will suspend its nuclear weapons program. The South Koreans and Chinese are inclined to take any deal, as they feel that the North Korean government can't last much longer. The Chinese, in particular, regard the current North Korean as a "troublesome child" that will eventually come to its senses. China sees this as but another chapter in thousands of years of Chinese-Korean relations.
But the United States is concerned that, while the communists are in power up north, they might be tempted to sell a nuclear weapon to terrorists. North Korea has been selling weapons, drugs and counterfeit currency to keep its dictatorship afloat. However, North Korea has not sold, as far as anyone knows, any of its chemical weapons.