Chinese antitrust officials are investigating General Motors in the wake of escalating tensions between Beijing and US President-elect Donald Trump, a person familiar with the matter said Wednesday.

Earlier, the state-run newspaper China Daily reported that China would slap fines on an unnamed US carmaker for monopolistic behaviour.

A penalty will be issued "soon" against an American firm for telling distributors to fix prices, the paper said in a front-page story, citing an "exclusive interview" with the director of the price supervision bureau in the country's top economic planner.

Chinese authorities often use state-controlled media to test out lines of attack and broadcast pointed messages while preserving a more neutral official stance.

Asked about the fine at the regular foreign ministry press briefing Wednesday, spokesman Geng Shuang said he knew "no details", adding that China welcomes US companies in principle but they must abide by local regulations.

Zhang Handong, director of the National Development and Reform Commission's price supervision bureau, which is conducting the probe, told the newspaper "no one should read anything improper into the timing" of the decision.

A spokesman for General Motors, the largest US automaker, said the company was in compliance with the law.

"GM fully respects local laws and regulations wherever we operate. We do not comment on media speculation," he said.

The story comes in the midst of a war of words between Trump and Chinese media, after the billionaire Republican businessman suggested he may reject the One China policy unless Beijing makes concessions on trade and other matters.

In an interview Sunday he said he did not see why Washington must "be bound by a One China policy unless we make a deal with China having to do with other things, including trade".

The president elect's protocol-breaking decision to take a call earlier this month with Taiwanese President Tsai Ing-wen has angered Beijing, which regards the island as a rogue province awaiting unification.

Trump, who takes office on January 20, has also repeatedly threatened to slap 45 percent tariffs on Chinese exports to the US.

It would not be the first time Chinese regulators have penalised foreign carmakers, with the commission in 2014 slapping multimillion-dollar fines on German and Japanese companies, drawing accusations of protectionism to boost local firms.

In an editorial, also published Wednesday, the China Daily took a swaggering tone, saying that if Trump wants to make Taiwan a bargaining chip, "he has no leverage".

"However, since he has indicated with his pre-office sound bites that his real interest is trade, let's talk about trade," it said.

The editorial singled out General Motors, noting that the US automaker had sold in China more than one-third of the nearly 10 million vehicles it sold last year.

"For the American economy to be great again," it added, "the US needs to cement its economic relations with China, rather than destroy them".