North Korea's sole major ally, China, would reduce aid to Pyongyang if it goes ahead with a planned nuclear test, state-run media said in an unusually frank warning yesterday.
The blunt comments came as opposition continued to pile up against the North's nuclear ambitions. Pyongyang announced plans for its third nuclear test on Thursday after a UN Security Council resolution imposed expanded sanctions against the Stalinist state for its weapons programme.
South Korea's President-elect Park Geun-hye said she could not tolerate the North's nuclear ambitions, and urged Pyongyang to return to negotiations.
Uncowed, North Korea's latest rejoinder yesterday was typically bellicose. The North's top body for inter-Korean affairs threatened South Korea with "physical counter-measures".
"Sanctions amount to a declaration of war against us," the Committee for Peaceful Reunification of the Fatherland said in a statement carried by the official Korean Central News Agency. "If the South Korean puppet regime of traitors directly participates in the so-called UN 'sanctions', strong physical countermeasures would be taken," it added.
North Korea's top military body had threatened the nuclear test to boost its ability to strike the United States, vowing more long-range rocket launches in an "all-out action" against its "sworn US enemy".
Even China, North Korea's longtime patron, could not bite its tongue.
"If North Korea engages in further nuclear tests, China will not hesitate to reduce its assistance to North Korea," Beijing's Global Times said in an editorial.
"Just let North Korea be 'angry'. We can't sit by and do nothing just because we are worried it might impact the Sino-North Korean relationship."
The same comments appeared in the Chinese version of the article. The paper is owned by People's Daily, the official mouthpiece of the Communist Party, and normally takes a nationalistic tone on foreign relations.
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 .
"China has a dilemma: there's no possible way for us to search for a diplomatic balance between North Korea and South Korea, Japan and the US," the Global Times said.
"We should have a pragmatic attitude to deal with the problems and pursue the optimal ratio between our investment of resources and strategic gains.
"China hopes for a stable peninsula, but it's not the end of the world if there's trouble there."
The editorial also expressed discontent at what it saw as North Korean criticism of Beijing for backing the UN resolution, which only passed after lengthy negotiations between the US and China.
Envoys said Beijing had sought to shield Pyongyang from tougher measures. "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.
China's Foreign Ministry spokesman, Hong Lei , said on Thursday that 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 left the forum in 2009.
In Davos, Switzerland, Rhee In-je, a special envoy for South Korea's new president, waded in.
"President-elect Park makes it clear that North Korea's nuclear ambitions and further provocations against the South will not be tolerated," Rhee said. "In particular, she strongly urges North Korea to refrain from further worsening the situation by conducting a third nuclear test."
Additional reporting by Associated Press