TSMC is signaling to the Trump administration that any plan to tariff foreign-made chips risks derailing the company’s $165 billion investment in Arizona semiconductor factories.

The warning comes after the Commerce Department solicited public comment on the US potentially tariffing foreign-made semiconductors to help encourage domestic chip manufacturing. In its letter to the agency, TSMC said such tariffs could threaten demand for electronics and reduce the company’s revenue.

“Diminished demand could create uncertainty around the timeline for the construction and operation of our Arizona fabs. It could also undermine TSMC’s financial capacity to timely execute its ambitious Arizona project,” the company said.

TSMC—which manufactures chips for Apple, AMD, Nvidia, and even Intel—added that: “Lower market demand for our leading US customers’ products may consequently reduce demand for TSMC’s manufacturing capacity and service onshore.”

In March, TSMC announced an additional $100 billion investment in three new fabs in Arizona, for a total of six. But so far, only one of the fabs has started producing processors, forcing TSMC to rely on its factories in Taiwan for most chip manufacturing.