General Motors is abandoning a previous forecast for solid profit growth this year as a result of the uncertainty created by President Trump’s trade policies, the automaker said on Tuesday.

The Trump administration imposed a 25 percent tariffs on imported cars this month and has said it will impose a 25 percent duty on imported parts on Saturday. About half the cars that G.M. sells in the United States in a typical year are made abroad, mostly in Canada and Mexico.

“We are not going to give any more forward guidance on tariffs until we have more clarity,” the company’s chief financial officer, Paul Jacobson, said in a conference call with reporters. “We don’t want to put out a number from the company that is a guess amidst what the administration might do.”