The US economy grew at an annual pace of 3.6 percent in the third quarter of the year, up from an initial estimate of 2.8 percent, revised figures have shown.
The growth rate was the fastest since the first quarter of 2012.
The third-quarter performance was an improvement on the 2.5 percent pace seen in the previous three months.
But the upward revision was mainly driven by a big jump in businesses restocking their inventories, the Commerce Department said.
The annualised growth figure was equivalent to a quarter-on-quarter increase of 0.9 percent, revised up from 0.7 percent.
The pace of growth in consumer spending – which accounts for about two-thirds of US economic activity – slowed from the previous quarter.
Consumer spending grew at a revised annual pace of 1.4 percent, down from 1.8 percent in the April-to-June period and the slowest rate since late 2009.
The inventory build-up consists of products that have been produced but not yet sold, such as cars.