ZURICH (Reuters) - Switzerland's main business lobby on Thursday rejected U.S. tariffs on Swiss imports as harmful and unjustified, as the country's government stressed the importance of respecting international law.

U.S. President Donald Trump on Wednesday imposed a 31% tariff on imports from Switzerland compared with 20% on goods from the European Union and 10% from Britain.

Business group Economiesuisse said there were no plausible grounds for the U.S. tariffs, noting that Switzerland had abolished industrial tariffs from the start of 2024 and already had lower import tariffs than the United States.

"Today's escalation in trade policy represents a serious burden for the Swiss export industry," Economiesuisse said, calling the tariffs "harmful and unjustified."

Trump wants to reduce the U.S. trade deficit, and Switzerland runs a substantial surplus in goods trade.

Still, Economiesuisse said that if services are included, trade between the two countries is almost balanced.

The group also noted that pharmaceutical products are not affected by Trump's April 2 executive order. Chemical and pharmaceutical products made up over half of Swiss exports to the U.S. in 2024, according to Swiss government data.

Shortly after Trump announced his tariff plan, Swiss President Karin Keller-Sutter said her government had taken note of the decision and would quickly determine its next steps.

"The country's long-term economic interests are paramount. Adherence to international law and free trade remain core values," she said in a social media post.

The United States is Switzerland's single-biggest export market, and the government has been at pains to stress the Swiss contribution to the U.S. economy. Switzerland is the sixth-biggest foreign investor in the United States.

Still, its agricultural sector is one of the most heavily subsidised among members of the Organisation for Economic Cooperation and Development (OECD) industrialised countries.