Consumer prices in the US rose by more than expected last month, driven by higher costs for rent and fuel.
The inflation rate, which measures the pace of price rises, was 3.7% over the 12 months to August, the Labor Department said, up from 3.2% in July.
The figures underscore the challenges facing officials trying to stabilise prices, which soared last year at the fastest pace in decades.
The inflation rate has dropped significantly from its peak last year.
But analysts said the US central bank, which aims to keep inflation at 2%, is likely to remain worried that the problem has not been resolved.
The bank has already raised its benchmark interest rate to the highest level in 22 years, targeting a range of 5.25% to 5.5%,in an effort to contain price rises.
It is due to meet later this month to consider whether further increases will be necessary.
Wednesday’s report showed fuel prices were the main driver of the jump in consumer prices from July to August. Monthly inflation was 0.6%, the highest since June 2022.
Stripping out food and fuel, where price swings are common, prices still rose by 0.3%, more than expected.
Housing costs, which many analysts had expected to start cooling this year and make up a major part of the US consumer price index, also rose for the 40th month in a row.
Analysts said the Federal Reserve is still unlikely to raise interest rates at its meeting, especially since rate rises have little influence over fuel prices, which were the biggest contributor to the rise in inflation in August.