WASHINGTON—Howard Lutnick’s journey from Wall Street veteran to one of President Trump’s most hawkish trade advisers began with a speech at an October campaign rally at Madison Square Garden. Lutnick extolled the virtues of tariffs and argued that the duties could at least in part replace the U.

He noted those tariffs were separate from a broad effort by the Commerce Department, the U.S. Trade Representative’s office and the Treasury Department to review trade relations and tariffs by April 1.

The billionaire Wall Street CEO fielded questions about tariffs, China's AI progress, broadband access, allegiance to Trump and the revival of American mining and semiconductor production.