CHINA warned the US yesterday against launching a “protectionist” probe into Beijing’s trade rules forcing foreign firms to transfer technology.

Commerce Ministry spokesman Gao Feng said Washington was disrupting the international trading order by carrying out the “Section 301” investigation under its own laws instead of through the World Trade Organisation (WTO).

“If the United States insists on unilateral and protectionist practices that will undermine the interests of China, we will take all necessary measures and resolutely safeguard the legitimate rights and interests of China,” he said.

US President Donald Trump ordered the probe into whether Beijing uses market access restrictions or other tools to compel foreign companies to hand over technology in August, three months before his state visit to Beijing.

A report could be released as early as this month.

If the investigation concludes Beijing acted improperly, Washington could seek remedies either through the WTO or outside it.

Mr Gao gave no indication of how Beijing might respond, but Chinese law gives regulators broad discretion over what foreign companies can do in China.

The spokesman also criticised last week’s decision by a Washington committee to block the sale of cash wire service MoneyGram to Chinese billionaire Jack Ma’s Ant Financial Group, on the grounds of “national security.”

“We regret to note that normal commercial investment and mergers and acquisitions conducted by Chinese enterprises in the United States are once again hindered by so-called ‘national security’,” Mr Goa said.

Meanwhile China’s State Administration of Foreign Exchange (Safe) denied reports Beijing might stop buying US debt bonds as a sanction.

Safe insisted it was a “responsible investor” for both the reserves and “participating markets,” calling the reports “fake news.”

China owns at least $1.2 trillion (£900 billion) in US debt.

In neighbouring Cambodia, Prime Minister Hun Sen and his Chinese counterpart Li Keqiang signed several agreements to develop the country’s infrastructure, agriculture and health care, totalling several billion dollars.

Cambodia’s Supreme Court dissolved the main opposition Cambodia National Rescue Party last November after authorities accused it of plotting a coup with US assistance.