"Strongly regret," and "unfair" were some of the reactions from trade partners around the world as the U.S. doubles tariffs on steel imports.

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.