Shares in Novo Nordisk, the Danish maker of the blockbuster diabetes and weight-loss treatments Ozempic and Wegovy, saw shares drop 4.5% shortly after trading got under way in Copenhagen.

Shares in Britain’s AstraZeneca fell 2.8% in London, while Sanofi fell 1.1% in Paris.

Meanwhile shares in Novartis shed 0.9% and Roche 1.0% after Trump announced Swiss goods will face a 39% tariff starting next week.

Trump told major pharmaceutical firms Thursday to lower prices or face punishment, as he moved to give Americans relief from medicine costs much higher than elsewhere in the world.

In letters to 17 drug companies published on his platform Truth Social, Trump said he wants the firms to work with his administration to institute a series of changes within 60 days.

“If you refuse to step up we will deploy every tool in our arsenal to protect American families from continued abusive drug pricing practices,” Trump wrote without specifying what the consequences would entail.

Trump is following up on an executive order he signed in May to address US drug prices that are among the highest in the world – more than three times what people in similarly developed countries pay, the White House said Thursday.