China has a "unique responsibility" to tackle the issue of North Korea, the top US military commander has said.
Speaking in Seoul, Admiral Mike Mullen said Beijing had "unique influence" over Pyongyang which it should use to curb its behaviour.
His comments came after talks with senior officials in the wake of last month's deadly shelling of a South Korean island.
As the talks began, North Korea conducted military drills in the area.
Tensions on the Korean peninsula have been extremely high since North Korea's 23 November shelling of Yeonpyeong, a small South Korean island close to the disputed western sea border.
Two soldiers and two civilians were killed in the shelling, which Pyongyang said was a response to South Korean military exercises. BBC News
