The rulings against the levies in two federal courts – the U.S. Court of International Trade and the U.S. District Court in Washington, D.C. -- centered on Trump's unprecedented invocation of the International Economic Emergency Powers Act as a legal justification for tariffs.

Trump said he would increase steel import tariffs to 50 percent, a move expected to impact U.S. manufacturers and trade relationships with Canada and China.

President Donald Trump returned to the White House in January determined to overturn decades of American policy and build a tariff wall around a U.S. economy that used to be pretty much wide open to foreign products.