Americans saw prices rise two percent in the year to March according to the Commerce Department's personal consumption expenditures index published on Monday. The figure, which is closely watched by the Federal Reserve as a sign of broader inflation levels, is approaching the maximum the central bank normally considers sustainable.
Energy and food costs rose 18.7 percent against March 2009, up almost four percentage points compared with February.
Without food and energy spending the inflation level remained stable at 1.3 percent.
The Federal Reserve last Wednesday vowed to keep historically low interest rates for an "extended period," amid "subdued" inflation trends.
Pointing to a slightly quickening economic recovery, the Fed said labor and housing markets showed glimmers of improvement and spending had ticked up.
That impression was reinforced Monday by the Commerce Department, which said spending rose for the sixth consecutive month in March, up by 0.6 percent.
Seasonally adjusted figures showed spending, a key driver of the US economy, rose as Americans saved less.