Pyongyang's claim to have tested a hydrogen bomb on Wednesday has put China, one of its few remaining allies, in a quandary as Beijing seeks to solidify its position as a global power without compromising the region's power balance.
Former U.S. undersecretary of state for political affairs Nicholas Burns said the events represented a test for China's leaders.
"China wants to be a recognized power in Asia and globally as its military and economy grow. Great powers need to take responsibility to put out fires and deal with reckless states."
Because China is North Korea's biggest trading partner and main source of aid, it holds influence over the pariah state, making it an essential player in the current conflict.
But these ties, which date back to the Korean War, have weakened since the rogue nation began testing nuclear weapons in 2006. Chinese authorities have since joined the international community in calling for denuclearization and supported United Nations (UN) sanctions.