China has warned the incoming Trump administration that any attempt to challenge the “One China” policy could affect peace in the Taiwan Strait.
A Beijing spokesman said that interference may also damage developing US-China relations.
Under the “One China” policy, the US has formal ties with China rather than the island of Taiwan, which China sees as a breakaway province.
However, Donald Trump has expressed doubts about continuing to abide by the policy.
The president-elect had already angered China by taking a phone call from Taiwan’s President Tsai Ing-wen, and then tweeting about it.
On December 12, China said it was “seriously concerned” by Donald Trump’s comments, and urged sensitivity around the issue.
However, An Fengshan, a spokesman for China’s policy-making Taiwan Affairs Office, went further on December 14, warning of more serious consequences.
He said: “Upholding the <<One China>> principle is the political basis of developing China-US relations, and is the cornerstone of peace and stability in the Taiwan Strait.
“If this basis is interfered with or damaged then the healthy, stable development of China-US relations is out of the question, and peace and stability in the Taiwan Strait will be seriously impacted.”
An Fengshan’s comments came as Admiral Harry Harris, head of the US Pacific Command, vowed the United States will keep challenging Beijing’s “assertive, aggressive behavior in the South China Sea”.
Speaking to Australian think tank the Lowy Institute in Sydney, Admiral Harry Harris said: “We will not allow the shared domains to be closed down unilaterally, no matter how many bases are built on artificial features in the South China Sea.
“We will co-operate where we can but we will be ready to confront where we must.”
Beijing has been developing artificial islands capable of hosting military planes in the region.
The Chinese government also insists on sovereignty over virtually all the resource-endowed South China Sea, despite rival claims from its South East Asian neighbors.
Washington has repeatedly said it does not recognize the claims, and has sent warships into the area to assert the right to freedom of navigation.