North Korea's sole major ally China will decrease aid to Pyongyang if it goes ahead with a planned nuclear test, state-run media said in an unusually frank warning on Friday.
China is the North's leading energy supplier and trade partner and is seen as one of the few nations able to influence Pyongyang's behaviour, with the comments adding a distinctive edge to its typical official calls for stability and dialogue.
"If North Korea engages in further nuclear tests, China will not hesitate to reduce its assistance to North Korea," the Global Times, which is close to the ruling Communist Party, said in an editorial.
"China hopes for a stable peninsula, but it's not the end of the world if there's trouble there," it added.
"We should have a pragmatic attitude to deal with the problems and pursue the optimal ratio between our investment of resources and strategic gains."
The editorial also expressed discontent at North Korean criticism of Beijing for backing a UN Security Council resolution this week that condemned Pyongyang's rocket launch last month and imposed expanded sanctions.
The resolution only passed after lengthy negotiations between the US and China, which wields a Security Council veto and sought to shield Pyongyang from tougher measures, envoys said.
"After putting a lot of effort into amendments for the draft resolution, China also voted for it. It seems that North Korea does not appreciate China's effort," the Global Times said.
When Pyongyang announced on Thursday it would carry out a third nuclear test, without specifying when, Beijing called for restraint and dialogue.
Foreign ministry spokesman Hong Lei said China hoped all parties would "stay calm, be discreet in words and deeds and look at the long-term interest and push for the resumption of the six-party talks".
The talks are chaired by China and also involve the two Koreas, the United States, Japan and Russia.
Their aim has been to convince Pyongyang to abandon its nuclear programme in return for aid and security guarantees, but the process has been moribund since the North abandoned the forum in 2009.