Chong Sho-Hu, professor of international relations at Beijing's Renmin University, said Pyongyang was "standing on the edge of a deep cliff" and warned that "one light blow" could push it off the precipice.
He added the long-standing relationship between the two countries should be determined by the "national interest" rather than friendships and enemies.
"North Korea is now in an awkward situation. No country on earth has come under such tough sanctions. If North Korea does not do anything and just sits there, this regime and this country will sit to death," he told BBC Radio 4.
"But if North Korea is there to take a further military provocation or nuclear test - an ICBM test - then I think North Korea will seek to die."
Presenter Tim Franks then asked: "So you think one more nuclear test could be the breaking point?"
He replied: "I think now North Korea is standing on the edge of a deep cliff and one light blow could push this country off the cliff."
Tensions between the countries have been escalating for months, but China has insisted it would not want to see military action taken to resolve the crisis.
It comes some weeks after China's foreign minister Wang Yi warned the situation on the Korean peninsula was getting more serious by the day and could not be allowed to spin out of control.
In September, Beijing's ambassador to the US warned China would never accept North Korea as a nuclear weapons state, just hours after leader Kim Jong-un said his country was on course to achieve that “final goal”.
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