U.S. inflation accelerated in August while jobless claims hit a four-year high, leaving the Federal Reserve trapped.

The numbers: Fresh worries about inflation soured Americans on the economy in early August, underscoring lingering anxiety about the highest U.S. tariffs in decades and a further rise in unemployment.

President Donald Trump’s tariffs continue to drive expectations for short-term inflation higher, but encouragingly for the Federal Reserve, long-term estimates haven’t taken off. Median inflation ...