WASHINGTON (AP) — Rising energy costs drove U.S. consumer prices higher in December, and American workers' earnings couldn't keep up.

The Labor Department said Tuesday that its consumer price index rose 0.2% last month, lifted by a 2.8% increase in gasoline prices. Over the past year, consumer inflation is up 2.3%. Excluding volatile food and energy prices, so-called core consumer inflation rose just 0.1% in December and 2.3% over the past year.

Inflation is running close to the Federal Reserve's 2% annual target. The Fed cut short-term interest rates three times last year, partly to protect a record-breaking U.S. economic expansion from the effects of President Donald Trump's trade war with China.

The Labor Department also reported that workers' hourly earnings, adjusted for inflation, fell 0.1% in December after rising 0.1% in November. Over the past year, workers' hourly earnings rose 0.6%. But they worked fewer hours, so inflation-adjusted weekly earnings showed "essentially no change'' over the past year, the department said.

Over the past year, gasoline prices are up 7.9% and the cost of shelter has risen 3.2%. Used-car prices are down 0.7%, and clothing prices have fallen 1.2%.