President Donald Trump said he may broaden the scope of U.S. tariffs on imports to include automobiles, pharmaceuticals and semiconductors.

In remarks to reporters Tuesday, Trump said the duties would be around 25% and “go very substantially higher over a course of a year.” The president did not indicate whether the new tariffs would apply to all vehicles coming into the U.S. or be targeted toward certain countries but said they could start as early as April 2.

However, the threat represents a broadening in the administration’s aggressive trade policy that already has included 25% tariffs on steel and aluminum imports set to take effect in March.

The nations with the biggest auto exports to the U.S. are Mexico, Japan and Canada.

Trump said the tariffs already are having the desired effect, with companies domiciled overseas wanting to come back to the U.S.

On pharmaceuticals, the nation feeling the biggest impact likely would be Japan and India. On semiconductors, Trump did not indicate when they would happen. Those levies would impact Taiwan Semiconductor, which provides chips to companies including Nvidia and Apple.