China and America disagree on how to deal with North Korea. The Chinese prefer to have a working dictatorship in North Korea, and are not too concerned about the North Korean military or North Korean nuclear weapons. What China fears the most is a collapse of the communist government in North Korea, and the flood of refugees coming into China. So the Chinese prefer to prop up the North Korean government, and nudge them more towards economic reform. There has already been a lot of reform, but much more is needed before there is substantial positive change. The U.S. does not want to give the North Koreans any more goodies unless North Korea gives up its nukes, which the U.S. sees as weapons the North Koreans may be tempted to sell to terrorists. The North Koreans have done business with terrorists, and anyone with lots of cash, before. The Chinese don't see this as likely, and have told the North Koreans not to even think of putting nukes up for auction. South Korea generally agrees with China.