“Core” C.P.I., which more closely reflects underlying inflation by removing volatile food and energy prices, also showed little improvement. It rose 0.4 percent from December or 3.3 percent on a year-over-year basis, both higher than economists expected. The monthly increase in core prices was the highest since April 2023.

Consumer prices rose 3%, extending a recent pattern of increases at the start of the year that likely derails the prospect for Federal Reserve rate cuts anytime soon.