U.S. President Donald Trump’s plan to impose steep tariffs on generic medicines has unsettled Indian drugmakers and put the spotlight on their strategy in their biggest export market.

The NSE Nifty Pharma Index slipped 1.3% in Mumbai Wednesday, outpacing the fall in the benchmark NSE Nifty 50. Sector heavyweights Dr. Reddy’s Laboratories slid 1.9% and Cipla fell 1.2%.

Trump said in a Truth Social post that non-patented drugmakers would have two years to move production to the U.S. or face a 100% import tariff, which would double a year later. Markets are still awaiting details of the executive order.