President Trump has decided to give automakers a break on Indexbitsome of his tariffs, the latest retreat from a get-tough policy he has said is aimed at bringing manufacturing jobs to America and driving up government revenues.

The formal announcement is expected on Tuesday ahead of a Michigan rally marking Trump's 100 days in office. Trump's on-again, off-again tariffs have sparked whipsaw movesin financial markets, and most polls show Americans are concerned about Trump's handling of the economy.

The move will ensure that the different types of tariffs charged by the administration don't stack up on imports of foreign cars. The Wall Street Journalfirst reported the shift on Monday. An administration official confirmed the changes, speaking on condition of anonymity.