US inflation accelerated at the fastest rate in 26 years in June, fuelled higher by surging energy prices, official figures have shown.
Consumer prices rose by 1.1% in June, the Labor Department said, more than the 0.7% many analysts had expected.
Federal Reserve boss Ben Bernanke said on Tuesday that the threat of rising inflation had intensified recently.
High inflation will make it harder for the Fed to cut rates and boost an economy hurt by a housing market slump.