WASHINGTON (NBC News) – Gary Cohn, President Donald Trump’s top economic adviser, resigned Tuesday.

The departure – following reports that Cohn, the National Economic Council director, had opposed Trump’s plan for large tariffs on imported steel and aluminum – comes as the latest in a string of exits of top officials in the administration.

The wealthy former Goldman Sachs banker played a key role on the president’s reform package, with Trump praising him in a statement Tuesday for doing a “superb job in driving our agenda, helping to deliver historic tax cuts and reforms and unleashing the American economy once again.”

At the Trump event Tuesday at the White House that Cohn skipped, the president reaffirmed his support for tariffs.

Cohn had been working in recent days to assure allies that no tariffs policy had yet been signed, and that their concerns over the move would be taken into consideration.