The Trump administration said it plans to announce measures as early as Tuesday to ease the impact of tariffs on imported cars and car parts to give automakers more time to relocate production to the United States.

Tariffs of 25 percent on imported vehicles and on auto parts will remain in place. But the tariffs will be modified so that they are not “stacked” with other tariffs, for example on steel and aluminum, a White House spokesman said. Automakers will not have to pay tariffs on those metals, widely used in automobiles, on top of the tariffs on cars and parts.

In addition, automakers will be reimbursed for some of the cost of tariffs on imported components. The reimbursement will amount to up to 3.75 percent of the value of a new car in the first year, but will be phased out over two years, the spokesman confirmed.