WASHINGTON—President Donald Trump signed executive orders on Thursday raising levies on some medications and refining calculations on steel tariffs.

Pharmaceutical drugs produced outside the United States are subject to 100 percent tariffs, unless manufacturers agree to onshore production and offer most-favored-nation pricing.

The Commerce Department is authorized to reduce levies to 20 percent for companies that invest in American facilities and remove the tariffs entirely for those that agree to both conditions.

Generic medications are exempt from the tariffs for one year, with a reassessment scheduled for 2027.

Exceptions were granted, lowering tariffs to 15 percent for the European Union, Switzerland, Japan, and South Korea, and a 10 percent levy for the United Kingdom.

Reduced rates reflect prior commitments with trading partners, according to a senior administration official.

The UK was awarded a lower tariff “because they were the first ones who did this deal, and they committed to raise their prices for pharmaceuticals, and they have actually done so,” the official told reporters during a background call on April 2.

According to the order, the action is necessary to address concerns uncovered by an investigation led by Commerce Secretary Howard Lutnick that found “the present quantities and circumstances of imports of pharmaceuticals and pharmaceutical ingredients threaten to impair the national security and economy.”

Limited domestic production capacity is “threatening to limit United States access to life-saving medications in the event of global supply chain disruption due to geopolitical or economic disruption,” the order reads.

Trump negotiated deals with 13 pharmaceutical companies over the past year, securing $400 billion in domestic manufacturing investments.

Agreements with four more of the largest producers are nearing completion, according to the president.

He signed deals last year securing most-favored-nation pricing for Americans, which he described at the time as “the biggest thing ever to happen on drug pricing and on health care.”

Trump has sought to reduce the nation’s reliance on pharmaceutical imports by revitalizing domestic manufacturing.

More than half of all patented medications by volume sold in the United States are manufactured globally, according to the Food and Drug Administration.

Foreign government intervention “undermined the competitiveness” of U.S. companies, and is jeopardizing supply chains and threatening national security, the order states.

Medicines targeted by the tariffs include those used to treat rare diseases, autoimmune disorders, cancer, and other health conditions.

The president also signed an order simplifying the calculation for steel tariffs, now levied at 50 percent of U.S. steel prices and 25 percent for products containing more than 15 percent of the metal.

The changes are intended to mitigate efforts by some steel wholesalers and exporters to reduce the impact of tariffs by artificially lowering the stated value of the metal on the global market.