Donald Trump attracted criticism from China after the president-elect stated that the U.S. did not necessarily have to stick to the "One China" policy.
China's foreign ministry said in a scheduled briefing that it was extremely concerned with Trump's comments, with spokesman Geng Shuang telling reporters that the policy was the basis of relations between the world's two largest economies.
The government's official response came after the Communist Party-owned paper, Global Times, published an opinion piece with the headline: "Trump, please listen clearly, the One China policy cannot be traded" as it warned Trump that China cannot "be easily bullied".
"If Trump abandons the one-China principle, why should China need to be U.S.' partner in most international affairs?" said the paper, which is known for its extreme nationalistic views.
Most would think Trump is "ignorant like a child" in handling diplomacy, the paper added.
Its English language edition was less strident, with the paper citing a foreign affairs analyst chalking up Trump comments to "inexperience" in a piece entitled "Prevent 'immature' Trump being manipulated by conservative forces: analyst".
"As a businessman, he thinks it's quite normal to do business, but he hasn't realized that the Taiwan question is not a business to China. The Taiwan question is not negotiable," China Foreign Affairs University professor Li Haidong was quoted as saying.