(Reuters) -U.S. drugmaker Merck ( MRK ) is investing $1 billion in a new Delaware plant to expand its domestic production as it prepares to deal with President Donald Trump's tariffs, the Wall Street Journal reported on Tuesday.

The new facility will produce biologic drugs and an easier-to-use version of Keytruda, becoming the company's first in-house U.S. site to make the blockbuster cancer treatment, the report said.

Merck ( MRK ) said last week its biggest tariff exposure is through Keytruda and it has enough U.S. inventory for this year. It estimated $200 million in additional costs for the levies implemented to date.

The company expects the new facility to be able to roll out drugs by 2030, the WSJ report said, adding that it would create at least 500 onsite jobs and about 4,000 construction vacancies.

Merck ( MRK ) opened a $1-billion facility at its North Carolina site last month to boost U.S. production.

The Trump administration has been putting pressure on U.S. drugmakers to move their medicine productions to the country and announced probes into drug imports that set the stage for levies in the sector.

U.S. drugmakers, including Eli Lilly and Johnson & Johnson, have recently announced additional investments to boost domestic production amid the tariff threat.

Merck ( MRK ) did not immediately respond to Reuters' request for comment.