The US economy grew at an annual rate of 4.6% between April and June, faster than the previous estimate of 4.2%, according to revised figures from the US Department of Commerce. The revision was due to larger rises in exports and business investment.
Growth estimates are revised as more information about economic performance becomes available. The strong growth - the fastest since the end of 2011 - follows a 2.1% contraction in the first quarter.
This fall in economic output was blamed on harsh winter weather, which discouraged shoppers and hampered manufacturing.
The revised figures for the second quarter showed that exports increased by 11.1% from the previous three months, while business spending rose by 9.7%.
Growth in consumer spending, which accounts for more than two-thirds of US economic activity, was 2.5%, unchanged from the previous estimate.
Analysts said the new figures suggested the US economy was in rude health.
The data signals an even stronger rebound from the decline seen in the first quarter, when extreme weather battered many parts of the economy, said Chris Williamson at Markit Economics.
”However, the impressive gain in the second quarter looks to be far more than just a weather-related upturn, with evidence pointing to an underlying buoyant pace of economic expansion. Survey data in particular indicate that strong growth has persisted throughout the third quarter.