The Chinese dominance on North Korea has been once again on a fantastic display in the last two weeks, when the Chinese Premier visited Pyongyang on a three days official visit. China has been the only close ally of North Korea and is said to be behind the nuclear missile capabilities development of North Korea.
Now China has urged the South Korea + US + Japan combine to push for negotiations with North Korea to resolve all outstanding issues. The timing of the statement just tells how much influence China has on North Korea. United States does not have a real choice on the issue than to go for negotiations with North Korea.