Merck, the New Jersey-based drug giant, is spending $1 billion on a new Delaware factory to bring production of its best-selling cancer drug Keytruda to the U.S. and speed future drugs to market. Keytruda is currently made in Ireland and by contract manufacturers in the United States.

The Delaware facility will ensure a domestic supply of biologic drugs including the cancer drug Keytruda.

Merck announced on Tuesday that it is investing $1 billion in a new Delaware plant to expand domestic production as it prepares to deal with President Donald Trump's tariffs