The consumer price index (CPI) rose more than expected in April.
The gauge of inflation rose 0.4% month-on-month, the biggest jump since February 2013, and increased 1.1% year-on-year, according to the Bureau of Labour Statistics.
On a headline basis, CPI was lifted mostly by a rise in energy costs. The gas index spiked 8.1%, the highest for any item.
Average national gas prices have climbed steadily throughout this year as crude oil also recovered. But compared to April 2015, the gas index was still down 13.8%.
The overall energy index jumped 3.4%, its biggest rise in three years.
Shelter costs, which have been a big driver of headline inflation in the past, rose 0.3%.
Excluding volatile food and energy costs, core CPI rose 0.2% month-on-month, and rose 2.1% year-on-year, as expected.
Economists had forecast that CPI rose 0.3% month-on-month and 1.1% year-on-year according to Bloomberg, accelerating gains made in the prior period.
The Federal Reserve uses a different measure of inflation — personal consumption expenditures — which it runs a bit slower than CPI.
“Inflation should pick up in the months ahead, however, which will allow the FOMC to raise the fed funds rate at the end of this year,” said PNC chief economist Stuart Hoffman.
“Higher energy prices over the past couple of months are starting to push overall inflation higher, and pass-through from energy to other prices will put upward pressure on core inflation in the months ahead.”