President Trump is expected to announce further tariffs this week, probably including levies on semiconductors, as he moves forward with a trade investigation related to national security.

The move would raise the cost of importing chips, which are a vital component in electronics, cars, toys and other goods. The United States is heavily dependent on semiconductors from Taiwan and elsewhere in Asia, a reliance that Democrats and Republicans alike have described as a major national security risk.

Mr. Trump has argued that the tariffs would encourage companies to produce more chips domestically, though some critics have questioned how effective tariffs would be at relocating an industry largely centered in Asia.

Speaking Sunday night from Air Force One, the president said tariffs on electronics would “be announced very soon,” but suggested there might be room for exemptions.

“We’ll also talk to companies,” the president said. “You know, you have to show a certain flexibility. Nobody should be so rigid. We have to have a certain flexibility.”

The measures would come after Mr. Trump abruptly changed course on taxing electronic imports in recent days.