The United States doubled tariffs on steel and aluminium imports on Wednesday, activating a hike in the duties on the imported metals to 50% from the 25% rate introduced in March. The day also marks the Trump administration’s deadline for trading partners to submit their “best offers” to avoid further steep import duties set to take effect in early July.

U.S. tariffs on steel and aluminum imports doubled on Wednesday, as President Donald Trump continued to ratchet up levies on foreign metals that he claims will help revitalize American steel mills and aluminum smelters.

Trump and his aides have repeatedly shifted their stance on tariffs in the weeks since the president’s “Liberation Day” announcement.