U.S. President Donald Trump's 50% tariffs on most imported steel and aluminum went into effect on Wednesday, an increase from previous 25% rate that had been in place.

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

President Donald Trump has promised to hike nearly all of his tariffs on foreign steel and aluminum to a punishing 50% on Wednesday, a move that would hammer businesses from automakers to home builders,