Driven by rising energy costs, consumer prices rose by 1.1 percent in June, the sharpest rate in 26 years, the Labor Department reported this week.
Excluding food and energy prices, which rose by 6.6 percent last month, so-called core consumer prices increased by 0.3 percent, the report said.
Last month's gains nearly doubled price increases in May, which rose by 0.6 percent.
Earlier this week, Federal Reserve Chairman Ben Bernanke told a congressional committee that inflation would likely "move temporarily higher" in the months ahead.
According to the National Federation of Independent Business, small-business owners are citing inflation as a top concern for the first time since the early 1980s. In a survey released last week, more owners reported raising average selling prices in June to offset rising costs and lower earnings, the Washington D.C.-based lobby group said.
"The inflation problem is getting worse, not better, as the economy weakens," William Dunkelberg, the group's chief economist, said in a statement.