US President Donald Trump holds a signed proclamation regarding polysilicon imports as Commerce Secretary Howard Lutnick watches in the Oval Office of the White House in Washington, US, August 6, 2026. (Photo: VCG)

US President Donald Trump on Thursday signed an executive order imposing minimum import prices and a 15% tariff on products made from polysilicon, a key material for solar panels and semiconductors.

The minimum import prices will be set at $21 per kilogram for polysilicon and $100 per kilogram for polysilicon ingots and wafers, according to a White House proclamation. The new trade measures are scheduled to take effect on December 4.

Trump also directed the US Commerce Department to establish a program to encourage investment in domestic production of raw polysilicon and related downstream products.

According to a White House fact sheet, the measures are aimed at creating "a level playing field for American producers of these strategic goods," encouraging the "onshoring of these industries," and protecting "US national security and its defense and defense-adjacent industrial base."

According to the fact sheet, the US share of global polysilicon production capacity declined from 50% in 2005 to less than 2% in 2024.