Critics of President Trump's tariff policies have been waiting for the import taxes to raise the inflation rate. That effect may be beginning.

Trump has rolled back many of his steepest tariffs over recent months, including a sky-high levy on China, the top source of U.S. imports. In recent days, however, Trump announced plans to slap tariffs as high as 50% on dozens of countries, including 25% tariffs on top U.S. trade partners such as Japan and South Korea.