Secretary for Commerce and Economic Development Algernon Yau on Friday said authorities are seeking clarifications as to whether new additional tariffs on Chinese imports announced by the US also cover goods from Hong Kong.

US president Donald Trump announced on his social media overnight that he will slap extra 10 percent tariffs on Chinese imports from March 4, on top of additional 10 percent levies imposed earlier this month.

Speaking to reporters at a press briefing, the commerce chief said the US tariffs are "unreasonable", reiterating that SAR authorities are filing an official complaint to the World Trade Organisation (WTO) over the earlier tariffs move.

"We have to understand better the details of this [latest] imposition, whether the Hong Kong production and products are included or excluded, so we are making assessments for the time being and seeking clarification," Yau said.

"Actually the volumes of Hong Kong products trading with the US are very minimal, accounting for only 0.1 percent of the total exports of Hong Kong, so the impact is not very significant at the moment," he added.

US officials earlier confirmed that the first set of additional tariffs applies to Hong Kong, to which the SAR government responded by saying the US ignored the fact that Hong Kong is a separate customs territory as stated in Article 116 of the Basic Law and recognised by the World Trade Organisation.

Separately, Yau noted that Hong Kong is in discussions with Malaysia and Saudi Arabia on setting up economic and trade offices in the two countries.

He added that Hong Kong is exploring investment agreements with Saudi Arabia, Bangladesh, Egypt and Peru, while actively seeking to join the Regional Comprehensive Economic Partnership (RCEP).

On another note, the commerce chief said Hong Kong remains a major investment hub as 10,000 overseas companies had settled in the SAR by the end of last year, a 10 percent rise on the number at the end of 2023.

Yau said while about one fifth of those firms come from the mainland, 1,400 are from Japan and another 1,400 are from the US.

There are also about 720 firms from the UK and 520 from Singapore, which indicates that the city is attractive to foreign investors from various regions, he said.