Headline US consumer price inflation (CPI) rose in line with expectations in December, but stripping out volatile measure such as energy and food, the core rate rose at its fastest since last January.
The headline rate, which rose at a softer-than-expected 0.1% monthly rate to an annual pace of 2.1%, was held back in December by a 2.7% fall in petrol prices.
Core CPI rose at a monthly rate of 0.3% in December, beating expectations of a 0.2% rise, while the annual pace of inflation rose to 1.8% from 1.7% in November.
"The outsized core is due to a 1.4% jump in used auto prices - demand rocketed after the hurricanes in the summer, driving up auction prices," said Ian Shepherdson at Pantheon Macroeconomics.
The data were unlikely to have much influence on interest rate expectations, however, as the Federal Reserve prefers to take its measure of price pressures from personal consumption expenditure (PCE) data, published later in the month.
CPI figures have indicated higher levels of inflation all year, with the PCE measure trailing some way behind at 1.5% - well shy of the Fed's target rate of 2%.
Fed action unlikely
It appeared unlikely the Fed would take any action at its first rate setting meeting of the year.