Treasury Secretary Steven Mnuchin disputed claims Thursday that the Trump administration’s tariffs on Chinese goods resulted in shortages of medical supplies in the United States, noting that the tariffs had been waived.

“That’s absolutely just not the case, OK? [U.S. Trade Representative Robert] Lighthizer has waived tariffs on any critical items,” Mnuchin said on Fox Business. “We’ve continued to do that on critical items, so that’s just not the case. And I would say that we’re doing everything to make sure the supply chains stay open.” The Trump administration dropped tariffs on various medical emergency items but only last week after industry executives pressed the USTR to make exceptions.