North Korea's official media accused China by name on Wednesday, saying it has sided with the United States to exert more pressure on Pyongyang.

"China had better ponder over the grave consequences to be entailed by its reckless act of chopping down the pillar of (bilateral) relations," the North's state-run Korean Central News Agency said in rare direct criticism of the country's most important political and economic benefactor.

A commentary released by KCNA said China should "no longer try to test the limits" of North Korea's "patience but make (a) proper strategic option."