Models display jewelry at the Hong Kong International Jewelry Manufacturers' Show. Photo: AFP

Goods imported from Hong Kong must be marked “Made in China” to be sold in the United States as part of Washington’s punitive response to a sweeping clampdown on the city, US customs authorities were set to announce Tuesday.

Last month, President Donald Trump retaliated against Beijing’s imposition of a tough new security law in Hong Kong by removing trading privileges for the financial hub, which in 2018 sold goods worth $6.3 billion to the United States.

Among the biggest categories of these imports were electrical machinery, precious metals and stones, and plastics.

“With respect to imported goods produced in Hong Kong, such goods may no longer be marked to indicate ‘Hong Kong’ as their origin, but must be marked to indicate ‘China,'” said a draft document from US Customs and Border Protection.

It comes at a time of rapidly deteriorating relations between China and the US, though fears the world’s two biggest economies could renew their damaging trade war were tempered by weekend talks to renew a January tariffs pact.

Until recently, Washington had treated imports from Hong Kong differently from goods from the rest of China, in recognition of the city’s semi-autonomous status.

However after Beijing imposed the security law in June to quell last year’s huge and often violent pro-democracy protests, Mr Trump vowed that this would change.

The customs document said the move was in accordance with an executive order made by Mr Trump last month “due to the determination that Hong Kong is no longer sufficiently autonomous to justify differential treatment in relation to China”.

A 45-day grace period would be granted to importers following the announcement to allow them time to ensure no goods were marked “Made in Hong Kong”, it added.

Mr Trump’s order, signed on July 14, also ends preferential treatment for Hong Kong passports, revokes license exceptions for certain exports, suspends Washington’s extradition agreement with the city and stops any joint police training.

The United States last week imposed sanctions on a group of Chinese and Hong Kong officials, including city leader Carrie Lam, in response to the crackdown.

China condemned the sanctions as “barbarous” and imposed retaliatory sanctions on some senior American politicians and leading human rights campaigners.