The Labor Department announced on Wednesday the U.S. consumer price index (CPI) rose 0.4 percent m-o-m in December, following an unrevised 0.2 percent m-o-m gain in the previous month.

Over the last 12 months, the CPI increased 1.4 percent y-o-y after a 1.2 percent climb in the 12 months through November. This was the highest reading since September.

Economists had forecast the CPI to increase 0.4 percent m-o-m and 1.3 percent y-o-y in the 12-month period.

According to the report, the December advance in the all items index was driven by an 8.4-percent jump in the gasoline index, which accounted for more than 60 percent of the overall gain. The other components of the energy index were mixed, resulting in an increase of 4.0 percent for the month. The food index rose by 0.4 percent m-o-m in December, as both the food at home and the food away from home indexes went up 0.4 percent m-o-m.

Meanwhile, the core CPI excluding volatile food and fuel costs rose 0.1 percent m-o-m in December after an unrevised 0.2 percent m-o-m increase in the previous month.

In the 12 months through December, the core CPI surged 1.6 percent, the same pace as in the 12 months ending November.

Economists had forecast the core CPI to edge up 0.1 percent m-o-m and to jump 1.6 percent y-o-y last month.