Beijing has warned the incoming US administration that any attempt to challenge the “One China” policy could affect peace in the Taiwan Strait.
Interference may also damage developing US-China relations, a spokesman said.
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, US President-elect Donald Trump has expressed doubts about continuing to abide by the policy.
Mr Trump had already angered China by taking a phone call from Taiwan’s President Tsai Ing-wen, and then tweeting about it.
On Monday, China said it was “seriously concerned” by Mr Trump’s comments, and urged sensitivity around the issue.
