The United States economy grew at an annual rate of 5.7% in the last three months of 2009, Commerce Department figures show.
The figure is the a big rise from is a big rise from the previous quarter's growth rate of 2.2%, and is the second consecutive quarter of growth after the country's severe recession.
It suggests the country's economy is growing at its fastest pace for six years and confirms the US economy has left its year-long recession behind, the BBC reports.
However gross domestic product (GDP) shrank by 2.4% across 2009 as a whole, the worst annual performance since 1946.
The United States' GDP is expressed as an annualised rate, or annual pace, which shows what the three months' economic activity would mean if it carried on for a year.
Most of the growth came from increased manufacturing to rebuild inventories. Consumer spending - the biggest component of the US economy - was down on the previous quarter.