The 20% prices on Northern Ireland products entering the United States could cost local businesses at least 100 million pounds of lost sales, an economist said.
US President Donald Trump is expected to announce a new series of prices on Wednesday.
The British government has tried to negotiate an exemption but now expects the prices to be imposed on British goods.
Northern Ireland has sold goods worth 1.3 billion sterling in the United States in 2023, with a concentration in pharmaceutical products and industrial machines.
The prices are indeed taxes applied to goods imported from other countries.
Governments impose prices in the hope of protecting local manufacturers from international competition.
The Ulster University economist, Esmond Birnie, calculated a “direct and narrow” impact of 100 million pounds sterling in reduced sales from a tariff of 20%.
He said that the effects of the second and third round, such as a global reduction in world trade, could push the overall negative impact to 200 million pounds sterling at 300 million pounds sterling.
He added that even a drop of 100 million pounds sterling could still have a significant impact on overall economic performance.
“It represents only 0.2% of the overall GDP of Northern Ireland, or about 50 billion pounds sterling,” he said.
“However, if the growth of Northern Ireland in GDP this year is much less than 1% – and this is very likely – this would be equivalent to a quarter of economic growth.”
Stuart Anderson, from the NI Chamber of Commerce, said the United States was a really important market and called on the British government to “really answer, very clearly” after Wednesday’s announcement.
He added that it could be “difficult” if the EU and the United Kingdom react differently.
American prices could have a deeper effect on the economy of the Republic of Ireland.
Among EU countries, Ireland is the most dependent of the United States as an export market.
In 2024, nearly a third of total exports from the country raised in the United States – worth 73 billion euros (61 billion pounds sterling).
President Trump previously indicated his dissatisfaction at the manufacturing scale by American pharmaceutical companies in Ireland.
In the Irish Parliament, Taoiseach (Irish Prime Minister), Micheál Martin, said that investors in Ireland “made decisions” to see how the prices take place.
He said the EU would take a “strategic response” and that it will be important that any countermeasures have not aggravated the problems.
