Pyongyang reacted angrily to tougher sanctions after its third nuclear test . The United States and South Korea have been pushing for a new round of U.N. Security Council sanctions. But Beijing has struggled to control the angry rhetoric from its neighbor . Expert : China fears a North Korean collapse would spark a refugee crisis .
Pyongyang reacted angrily to tougher sanctions after its third nuclear test . Chinese trade with North Korea has been a lifeline for the isolated regime . But Beijing has struggled to control the angry rhetoric from its neighbor . Expert : China fears a North Korean collapse would spark a refugee crisis .