General Motors cheered on President Donald Trump for working with the company to refine auto tariffs, but warned that sustained protectionist policies could “significantly” hurt the industry down the road. 

Trump signed a March executive order implementing a 25% tariff on foreign-built vehicles starting April 3, with a few key auto parts subject to a tariff starting May 3. However, the president is expected to sign an executive order on Tuesday designed to soften the effects of those tariffs, according to reports. Import levies placed on foreign-made cars will reportedly not be subject to other tariffs, and some tariffs on foreign parts used on domestic cars could be removed as part of the order.