The White House said on Tuesday that top White House economic adviser Gary Cohn, a Wall Street banker who became a key architect of the 2017 tax overhaul within the Trump administration, is resigning. “It has been an honor to serve my country and enact pro-growth economic policies to benefit the American people, in particular the passage of historic tax reform. I am grateful to the President for giving me this opportunity and wish him and the Administration great success in the future,” Cohn said in a statement issued by the White House. Cohn’s resignation came after U.S. President Donald Trump said he would impose hefty tariffs on steel and aluminum imports. Trump’s pledge to impose tariffs prompted speculation Cohn might leave the White House because of his opposition to the policy. Cohn was the former president and chief operating officer of investment bank Goldman Sachs, and was hired by Mr. Trump after the 2016 presidential election.