The SAR government has expressed strong disapproval and discontent over the United States for imposing a fresh round of tariffs and cancelling a duty-free exemption on small parcels.

It called on Washington to withdraw the “bullying” measures.

US President Donald Trump earlier announced a raft of punishing tariffs targeting countries around the world.

He also signed an executive order to cancel a trade exemption known as "de minimis", which allows low-value packages from mainland China and Hong Kong to enter the country free of duties, from May 2.

"The US's measures are bullying and unreasonable, and grossly inconsistent with the World Trade Organisation (WTO) rules, willfully undermining the multilateral trading system which is the cornerstone for international trade," a Hong Kong government spokesperson said on Thursday.

"Once again, the government firmly requests the US to withdraw its so-called reciprocal tariff measures."

Responding to changes to the "de minimis" exemption, the administration said Hongkong Post will temporarily maintain postal services to the US without collecting any so-called tariffs on behalf of the US until May 2.

"The US has been repeatedly changing its policies unilaterally. Hongkong Post has requested the postal administration of the US to promptly clarify the matter and should not cause inconvenience to the public," the spokesperson said.

The administration also pledged to closely monitor and assess any unilateral measures of the US that are inconsistent with fair trade, saying it will defend the city's legitimate interests by, for example, filing a complaint to the WTO.