Americans hoping for some relief on inflation suffered a setback in February, as new data showed underlying price pressures intensifying even before the latest escalation in President Trump’s trade war.

The Personal Consumption Expenditures price index, after stripping out volatile food and energy items, climbed 2.8 percent in February from a year earlier, outpacing January’s annual pace. On a monthly basis, these “core” prices ticked up another 0.4 percent, higher than the monthly increase in January. Both were slightly higher than economists had expected.

Overall inflation came in at 2.5 percent, a level that sits well above the Federal Reserve's 2 percent target and has been more or less in place since November.

Consumer spending for the month rose 0.4 percent, reversing a decline seen in January despite falling short of what economists had forecast.

The latest data from the Commerce Department highlights the extent of the challenge the central bank is confronting. Its debate over what to do about interest rates has been complicated by a rapidly escalating trade war, one that has bred extreme uncertainty about the economic outlook.

On Wednesday, Mr. Trump announced 25 percent tariffs on cars and car parts imported into the United States and has vowed to unveil another set of tariffs next week.