From The New York Times:
After years of trying to find middle ground between the United States and North Korea, China now finds itself in a difficult diplomatic position with Pyongyang’s announcement that it has manufactured nuclear weapons and is suspending nuclear negotiations, Chinese foreign policy experts said today.
Chinese leaders have consistently urged the rest of the world, and especially the United States, to show more patience with North Korea. Beijing has consistently contended that it was unclear whether North Korea had developed nuclear weapons, notwithstanding a growing volume of American intelligence to the contrary.