US consumer prices rebounded in February as petrol prices rose for the first time since June.
There were also signs of an increase in underlying inflation pressures, which could keep a June interest rate increase on the table.
The US Labor Department said its Consumer Price Index increased 0.2% last month after declining 0.7% in January. That ended three months of declines in the index in a row.
In the 12 months to February, the CPI was unchanged after slipping 0.1% in January.
Economists polled by Reuters had expected the CPI to rise 0.2% from January and slip 0.1% from a year ago.
US Federal Reserve officials have long viewed the energy-driven weakness in inflation as transitory.
The Fed, which has a 2% inflation target, has kept its short-term interest rate near zero since December 2008.
Fed Chair Janet Yellen said last week policymakers could raise interest rates when they had "seen further improvement in the labour market" and were "reasonably confident that inflation will move back to its 2% objective over the medium term."
The so-called core CPI, which strips out food and energy costs, increased 0.2% in February after a similar gain in January.
In the 12 months to February, the core CPI rose 1.7%, the largest increase since November.
Crude oil prices fell 60% between June and January on fears of a global oil glut and the refusal of Saudi Arabia and other OPEC members to cut output. In February, Brent stabilised at around $60 and US crude at around $50.
Last month, US domestic petrol prices rose 2.4%, the largest increase since December 2013, after tumbling 18.7% in January.
Fuel prices had declined for seven consecutive months.
US food prices increased 0.2%, while clothing prices rose 0.3% in February after a similar gain in January.
There were also increases in airfares, new motor vehicle and used cars and trucks prices. However, the cost of medical care services declined for the first time since 1975.